Hello, I’m Kodak.
The Japanese word 世界 (sekai) is usually translated as “world.”
However, it does not always mean the entire planet.
Travel the world.
音楽の世界に入る。
Enter the world of music.
彼は自分の世界に閉じこもっている。
He is shut away in his own world.
物語の世界観が美しい。
The fictional world and atmosphere of the story are beautiful.
The core image is “the complete space or realm within a certain boundary.”
世界 (sekai) most commonly means the world.
It can refer to:
① all countries and regions of the world
② human society or the environment in which people live
③ a particular profession, field, or community
④ an imaginary, artistic, or personal world
⑤ the whole realm of existence in religious or philosophical contexts
Because sekai can describe both the largest possible world and a small personal realm, it appears frequently in Japanese songs, anime, games, novels, and everyday conversation.
See also: Beautiful Japanese Words in Songs
What Does Sekai Mean in Japanese?
Hiragana: せかい
Romaji: sekai
Basic meanings: world, society, realm, sphere, domain, community
The most useful meanings for beginners are:
All countries, regions, and people on Earth.
2. Human society or one’s lived world
The social environment in which a person lives.
3. A particular field or community
The world of art, sports, medicine, business, or another activity.
4. A fictional or imagined realm
The setting and reality of a story, anime, game, or dream.
5. A person’s own inner or limited world
The range of experiences and ideas that person recognizes.
Sometimes Japanese needs 地球 (Earth), 社会 (society), 世の中 (the world we live in), or 宇宙 (the universe) instead.
The Core Image of Sekai
Rather than memorizing several unrelated meanings, connect them through the idea of a bounded realm.
A sekai is the whole realm that exists within a certain frame or boundary.
If the frame is the Earth, sekai means the whole world.
If the frame is music, it means the world of music.
If the frame is a story, it means the story’s fictional world.
If the frame is one person’s awareness, it means that person’s inner world.
Ask “What boundary defines this world?”
世界は広い。
Sekai wa hiroi.
The world is vast.
科学の世界は奥が深い。
Kagaku no sekai wa oku ga fukai.
The world of science has great depth.
彼女の世界には音楽しかなかった。
Kanojo no sekai ni wa ongaku shika nakatta.
Music was the only thing in her world.
Each sentence uses a different boundary, but the core image remains the same.
Sekai as the Whole World
The most common meaning of sekai is all the countries, regions, and people of the world.
世界にはさまざまな文化がある。
Sekai ni wa samazama na bunka ga aru.
There are many different cultures in the world.
いつか世界を旅したい。
Itsuka sekai o tabi shitai.
I want to travel the world someday.
この歌は世界で愛されている。
Kono uta wa sekai de aisarete iru.
This song is loved around the world.
世界で愛されている means “is loved in the world” or naturally, “is loved worldwide.”
世界中: All Over the World
throughout the world
all over the world
everywhere in the world
世界中の人々がその試合を見た。
Sekaijū no hitobito ga sono shiai o mita.
People all over the world watched the match.
この料理は世界中で人気がある。
Kono ryōri wa sekaijū de ninki ga aru.
This dish is popular throughout the world.
世界の周り would sound like “the area surrounding the world.”
For “throughout the world,” use 世界中.
世界一: Number One in the World
the best in the world
number one in the world
the world’s largest, fastest, or greatest
彼は世界一速い選手です。
Kare wa sekaiichi hayai senshu desu.
He is the fastest athlete in the world.
これは世界一大きな花です。
Kore wa sekaiichi ōkina hana desu.
This is the largest flower in the world.
Sekai as Human Society or One’s Lived Environment
Sekai can refer not only to geography but also to the human environment and way of life surrounding someone.
外の世界をもっと知りたい。
Soto no sekai o motto shiritai.
I want to know more about the outside world.
彼らは住む世界が違う。
Karera wa sumu sekai ga chigau.
They live in different worlds.
本を読むと世界が広がる。
Hon o yomu to sekai ga hirogaru.
Reading books broadens your world.
Sekai as a Field, Profession, or Community
Japanese often uses ～の世界 for a professional field, specialized community, artistic sphere, or group with its own rules.
芸能界 — the entertainment world or industry
スポーツの世界 — the world of sports
政治の世界 — the world of politics
学問の世界 — the academic world
プロの世界 — the professional world
彼は十代でプロの世界に入った。
Kare wa jūdai de puro no sekai ni haitta.
He entered the professional world in his teens.
ファッションの世界では有名な人物です。
Fasshon no sekai de wa yūmei na jinbutsu desu.
She is a famous person in the fashion world.
社会 focuses more on society as an organized human system.
Sekai as a Fictional or Imaginary World
In anime, manga, games, films, and novels, sekai often refers to the reality in which the story takes place.
the world of the story
ゲームの世界 (gēmu no sekai)
the game world
架空の世界 (kakū no sekai)
a fictional world
魔法の世界 (mahō no sekai)
a world of magic
別の世界 (betsu no sekai)
another or different world
この物語は魔法が存在する世界が舞台です。
Kono monogatari wa mahō ga sonzai suru sekai ga butai desu.
This story is set in a world where magic exists.
まるで別世界に来たようだ。
Marude betsu sekai ni kita yō da.
It feels as if I have come to another world.
A luxury hotel, a peaceful island, or even a quiet room may feel like 別世界.
Sekai as a Personal or Inner World
自分の世界 (jibun no sekai) describes the reality, interests, thoughts, or perceptions that belong to one person.
彼は自分の世界に入り込んでいる。
Kare wa jibun no sekai ni hairikonde iru.
He is absorbed in his own world.
彼女は独特の世界を持っている。
Kanojo wa dokutoku no sekai o motte iru.
She has a unique inner or creative world.
音楽を聴くと、自分だけの世界に入れる。
Ongaku o kiku to, jibun dake no sekai ni haireru.
When I listen to music, I can enter a world of my own.
It can praise creativity and concentration, or criticize someone for ignoring other people and reality.
Sekai Kanji: What Do 世 and 界 Mean?
世界: せかい (sekai)
世: セ / セイ / よ
界: カイ / さかい
Total stroke count: 14
世 Means World, Age, or Generation
Stroke count: 5
Main ideas: the world, society, an age, a lifetime, a generation
世 appears in words connected with the world people live in and the passing of time or generations.
世間 (seken) — society; the public
現世 (gense) — this world; the present life
来世 (raise) — the next life
世代 (sedai) — generation
中世 (chūsei) — the Middle Ages
界 Means Boundary or the Realm Within a Boundary
Stroke count: 9
Main ideas: boundary, division, area, realm, social sphere
界 is a phono-semantic character formed from 田 and the sound element 介. Its original image is the boundary between fields.
限界 (genkai) — limit
業界 (gyōkai) — industry
政界 (seikai) — political world
視界 (shikai) — field of vision
天界 (tenkai) — heavenly realm
Historically, however, 世界 entered Japanese as a Buddhist term, so its origin is broader than simply combining two modern dictionary definitions.
The Origin of the Word Sekai
世界 was originally a Buddhist term translated from the Sanskrit lokadhātu.
In the traditional Buddhist explanation:
the three times: past, present, and future
↓
界
the spatial directions and the bounded realm
↓
世界
the total realm of time and space inhabited by living beings
The word later broadened from a religious or cosmological realm to mean human society, the Earth’s countries and regions, a particular field, or a personally perceived world.
A Japanese example is recorded as early as the year 818 in the Chinese-style poetry collection Bunka Shūreishū.
The familiar modern meaning “the whole world” developed later.
How to Pronounce Sekai
Hiragana: せかい
Katakana: セカイ
Romaji: sekai
Mora: せ・か・い (3 morae)
Pronounce the word in three even units:
se + ka + i
The ending かい (kai) contains two morae, か and い. In natural speech they connect smoothly, but do not pronounce the word like English “sky.”
This is a stylistic effect, not a completely different dictionary word.
How to Use Sekai in Japanese
1. 世界に: In the World
世界には知らないことがたくさんある。
Sekai ni wa shiranai koto ga takusan aru.
There are many things in the world that I do not know.
2. 世界で: In or Among the World
世界で最も高い山はエベレストです。
Sekai de mottomo takai yama wa Eberesuto desu.
The highest mountain in the world is Everest.
3. 世界の: World or Global
世界の歴史を学ぶ。
Sekai no rekishi o manabu.
Study world history.
4. ～の世界: The World or Realm of Something
彼女は芸術の世界で活躍している。
Kanojo wa geijutsu no sekai de katsuyaku shite iru.
She is active in the art world.
5. 世界が + Verb: The World Changes, Expands, or Ends
その出会いで私の世界が変わった。
Sono deai de watashi no sekai ga kawatta.
That encounter changed my world.
新しい言語を学ぶと世界が広がる。
Atarashii gengo o manabu to sekai ga hirogaru.
Learning a new language expands your world.
Common Expressions Using Sekai
all over the world
世界一 (sekaiichi)
number one in the world; the world’s best
世界的 (sekaiteki)
worldwide; global; world-class
世界観 (sekaikan)
worldview; the setting, atmosphere, and rules of a creative work
世界を変える (sekai o kaeru)
change the world
世界を救う (sekai o sukuu)
save the world
世界が広がる (sekai ga hirogaru)
one’s world or horizons expand
自分の世界 (jibun no sekai)
one’s own world
別世界 (betsu sekai)
another world; a completely different environment
世界の終わり (sekai no owari)
the end of the world
世界的な問題 ⇒ a worldwide or global problem
世界的な音楽家 ⇒ a world-famous or world-class musician
What Does Sekaikan Mean?
Traditional meaning: worldview; an interpretation of the world and human existence
Common creative-use meaning: the setting, atmosphere, visual identity, rules, and overall feeling of a fictional work
このゲームは独特の世界観を持っている。
Kono gēmu wa dokutoku no sekaikan o motte iru.
This game has a distinctive fictional world and atmosphere.
作者の世界観に共感した。
Sakusha no sekaikan ni kyōkan shita.
I related to the creator’s worldview.
It often means the unified reality a work creates through its setting, design, mood, and rules.
What Does Isekai Mean?
Hiragana: いせかい
Romaji: isekai
Literal meaning: different world / another world
異 (i) means different or unusual, so 異世界 refers to a world different from the ordinary one.
In anime, manga, light novels, and games, isekai commonly describes stories in which a character travels, is summoned, is transported, or is reincarnated into another world.
主人公は異世界に召喚された。
Shujinkō wa isekai ni shōkan sareta.
The protagonist was summoned to another world.
The modern genre label usually emphasizes the relationship between the ordinary world and the other world.
What Does Sekaikei Mean?
A loosely defined story type in which the personal emotions or relationship of an ordinary young protagonist are connected directly to a crisis affecting the whole world.
The term spread online around 2002 and is often applied to anime, manga, games, and light novels. There is no single universally accepted definition.
・an intimate relationship between a boy and a girl
・strong focus on the protagonist’s emotions
・a crisis involving the fate of the world
・little explanation of the wider society or political structures between the personal and global levels
Isekai focuses on another world.
Sekaikei describes a narrative structure connecting an intimate personal relationship with the fate of the world.
Why Sekai Appears So Often in Japanese Songs and Anime
Sekai is powerful in lyrics because it can be enormous or deeply personal.
Humanity, all countries, or everything that exists.
Sekai as two people’s shared reality
A private emotional world created by a relationship.
Sekai as personal perception
Everything the speaker can see, understand, or feel.
Sekai as a future that can change
A reality transformed through courage, love, or action.
Sekai as a fragile reality
A world that may collapse, disappear, or end.
Common lyric-like combinations include:
世界を救う — save the world
君のいる世界 — the world where you exist
二人だけの世界 — a world belonging only to the two of us
この世界で — in this world
世界の果て — the end or edge of the world
新しい世界 — a new world
閉ざされた世界 — a closed-off world
世界が終わる — the world ends
世界は回り続ける — the world keeps turning
The exaggeration is what gives the line its emotional force.
Sekai vs Chikyū vs Uchū vs Shakai
Sekai vs Chikyū: 世界 and 地球
the world as countries, people, society, experience, or a realm
地球 (chikyū)
the planet Earth as a physical astronomical body
世界には多くの国がある。
There are many countries in the world.
地球は太陽の周りを回っている。
Earth revolves around the Sun.
世界に住んでいる sounds odd because everyone normally understands that humans live in the world.
Sekai vs Uchū: 世界 and 宇宙
world or realm; sometimes the whole of existence in broad philosophical contexts
宇宙 (uchū)
outer space, the cosmos, or the physical universe
世界の人々と交流する。
Interact with people around the world.
宇宙には無数の星がある。
There are countless stars in the universe.
Sekai vs Shakai: 世界 and 社会
the world or a particular realm viewed as a complete sphere
社会 (shakai)
society as an organized system of human relationships and institutions
教育の世界で働いている。
I work in the world or field of education.
教育は社会にとって重要だ。
Education is important to society.
Sekai vs Yo no Naka: 世界 and 世の中
the world, a realm, or a field; can sound broad, spatial, or conceptual
世の中 (yo no naka)
the world people live in; society and the way life works
世界には美しい場所がたくさんある。
There are many beautiful places in the world.
世の中は思い通りにならない。
The world does not always go the way you want.
Use yo no naka when talking about real life, society, and how the world works.
Natural Example Sentences with Sekai
世界にはまだ知らない場所がたくさんある。
Sekai ni wa mada shiranai basho ga takusan aru.
There are still many places in the world that I do not know.
この映画は世界中で公開された。
Kono eiga wa sekaijū de kōkai sareta.
This film was released around the world.
彼女は世界的に有名な画家です。
Kanojo wa sekaiteki ni yūmei na gaka desu.
She is a world-famous painter.
世界一おいしい料理だと思う。
Sekaiichi oishii ryōri da to omou.
I think it is the most delicious food in the world.
留学して私の世界が大きく広がった。
Ryūgaku shite watashi no sekai ga ōkiku hirogatta.
Studying abroad greatly broadened my world.
彼は子どものころから映画の世界に憧れていた。
Kare wa kodomo no koro kara eiga no sekai ni akogarete ita.
He had admired the world of film since childhood.
この小説の世界観はとても独創的だ。
Kono shōsetsu no sekaikan wa totemo dokusōteki da.
The fictional world of this novel is very original.
森の中は町とは別世界のように静かだった。
Mori no naka wa machi to wa betsu sekai no yō ni shizuka datta.
The forest was so quiet that it felt like another world compared with the city.
一冊の本が私の世界を変えた。
Issatsu no hon ga watashi no sekai o kaeta.
One book changed my world.
君がいない世界なんて想像できない。
Kimi ga inai sekai nante sōzō dekinai.
I cannot imagine a world without you.
彼は周りの声を聞かず、自分の世界に閉じこもった。
Kare wa mawari no koe o kikazu, jibun no sekai ni tojikomotta.
He ignored the voices around him and withdrew into his own world.
もし世界が明日終わるなら、何をしますか？
Moshi sekai ga ashita owaru nara, nani o shimasu ka?
What would you do if the world ended tomorrow?
Common Beginner Mistakes
Mistake 1: Using Sekai When You Mean the Physical Planet Earth
世界には多くの文化がある。
Earth is a planet.
地球は惑星です。
Mistake 2: Translating “Around the World” as 世界の周り
Use 世界中 or a suitable phrase with 世界で.
It is popular around the world.
△ 世界の周りで人気がある。
This sounds as though something is popular around the outside of the world.
Mistake 3: Using Sekai for the Universe
Use 宇宙 when discussing outer space, galaxies, stars, or the physical cosmos.
Mistake 4: Assuming Sekai Always Means Something Geographically Large
音楽の世界, 子どもの世界, and 自分の世界 are bounded realms rather than the whole planet.
Mistake 5: Confusing Isekai and Sekaikei
異世界 means another world and commonly names a genre involving movement to such a world. セカイ系 refers to a loosely defined narrative pattern connecting personal relationships directly with a world-scale crisis.
Mistake 6: Treating 世界観 as Only “Worldview”
In philosophy, 世界観 means worldview. In everyday discussion of creative works, it often refers more broadly to the work’s setting, mood, visual identity, and internal rules.
FAQ About Sekai
What does sekai mean in Japanese?
Sekai most commonly means the world. It can also mean human society, a field or community, a fictional realm, or a person’s inner world.
How do you write sekai in Japanese?
It is normally written 世界 in kanji, せかい in hiragana, and セカイ in katakana.
What do the kanji in sekai mean?
世 can mean the world, an age, a lifetime, or a generation. 界 means a boundary, area, or realm within a boundary.
Is sekai the same as Earth?
No. 世界 refers to the world as countries, people, society, experience, or a realm. 地球 refers specifically to the physical planet Earth.
What is the difference between sekai and uchū?
Sekai means the world or a realm. Uchū means outer space or the physical universe.
What does sekaijū mean?
世界中 means throughout the world, all over the world, or everywhere in the world.
What does sekaiichi mean?
世界一 means number one in the world, the world’s best, or the world’s largest, fastest, or greatest in a particular category.
What does sekaikan mean?
世界観 traditionally means worldview. In discussion of fiction and art, it often means the work’s setting, atmosphere, design, and internal rules.
What does isekai mean?
異世界 literally means another or different world. It commonly refers to stories in which a character travels, is summoned, or is reincarnated into another world.
What does sekaikei mean?
セカイ系 is a loosely defined story type in which an intimate personal relationship is connected directly to a crisis affecting the whole world.
Why is sekai common in Japanese songs?
The word can describe the entire world, a personal emotional reality, a shared world between two people, or a reality that can change or end, making it useful for emotional lyrics.
Summary: Sekai Meaning and Usage
Sekai means the world, society, a realm, a field, or a personal or fictional world.
● Kanji
世界
● Core image
The complete realm that exists within a particular frame or boundary.
● Word origin
Originally a Buddhist term translated from Sanskrit, referring to a realm of time and space inhabited by living beings.
● Important related words
世界中 — all over the world
世界一 — number one in the world
世界観 — worldview or fictional world setting
異世界 — another world
セカイ系 — a personal-to-global narrative pattern
● Important distinction
世界 is not always the physical Earth. Use 地球 for the planet and 宇宙 for outer space or the physical universe.
Sekai is the whole reality contained within a certain boundary.
That boundary may be the Earth, human society, a profession, a fictional story, or one person’s heart and experience.
Related Articles
- Beautiful Japanese Words in Songs
- Kokoro Meaning: What Does 心 Mean in Japanese?
- Yume Meaning: What Does 夢 Mean in Japanese?
- Hikari Meaning: What Does 光 Mean in Japanese?
References
- Kanjipedia: 世界 — meanings including the whole Earth, all countries, society, a field, and the distinctive realm of an artistic work.
- Kotobank: 世界 — modern meanings, Buddhist origin, Sanskrit source, historical examples, and development of the word.
- Kanjipedia: 世 — readings, stroke count, and meanings including world, age, lifetime, and generation.
- Kanjipedia: 界 — readings, stroke count, meanings, and the character’s formation from 田 and 介.
- Kotobank: 世界観 — philosophical meaning and the common creative-work usage.
- Kotobank: セカイ系 — explanation of the term, common narrative characteristics, and its spread from around 2002.