LESSON NOTES · レッスンノート

N4Lesson notes · Oct 4, 2026

Life in Japanese: 命いのち, 人生じんせい, 生活せいかつ, 一生いっしょう — four words for one English word

"Life" in Japanese depends on which life you mean: 命いのち (いのち) is life as being alive, 人生じんせい (じんせい) is the story of a person's life, 生活せいかつ (せいかつ) is daily living, and 一生いっしょう (いっしょう) is a whole lifetime. "Save a life" is 命いのち, "life is short" is 人生じんせい, "life in Tokyo" is 生活せいかつ.

English uses one word for all of these, and learners usually pick the first one they found in a dictionary. The result is sentences that are understandable but odd, like using 命いのち for "my life in Japan". Once you see what each word points at, the choice becomes quick. This post explains the four main words, two more you will meet, and a couple of everyday expressions, like 人生じんせい初はつ, that make conversation more fun.

How do you say "life" in Japanese?

What is 命いのち?

命いのち (いのち) is life itself: the state of being alive, the thing you can save or lose.

命いのちを大切たいせつにしてください。 — Please take care of your life. (polite, a serious message) あの人ひとは私わたしの命いのちの恩人おんじんです。 — That person saved my life. (polite, literally "the benefactor of my life")

命いのち is precious, physical and serious. Use it for saving lives, risking your life, and the life of animals and plants too. 命いのちがけ (いのちがけ) means "risking your life", and it is common in anime battles and in serious efforts: 命いのちがけで守まもる, "protect with my life".

What is 人生じんせい?

人生じんせい (じんせい) is human life as a journey: the course of one person's life, from birth to old age.

人生じんせいは短みじかい。 — Life is short. (neutral, a reflection) この本ほんは私わたしの人生じんせいを変かえた。 — This book changed my life. (neutral)

If you are talking about choices, experiences, success, regret or the meaning of life, the word is 人生じんせい. It is the life you look back on, not the heartbeat.

What is 生活せいかつ?

生活せいかつ (せいかつ) is daily life, the way you live day to day: housing, work, money, routine.

日本にほんの生活せいかつに慣なれましたか。 — Have you gotten used to life in Japan? (polite, a very common question) 東京とうきょうの生活せいかつは便利べんりだけど、忙いそがしい。 — Life in Tokyo is convenient but busy. (casual)

生活せいかつ is practical. 生活費せいかつひ (せいかつひ) is living costs, and 食生活しょくせいかつ (しょくせいかつ) is your eating habits. If you could describe it with a weekly schedule, it is 生活せいかつ. Our post on getting used to things uses 生活せいかつ in many examples.

Beyond the basics

What is 一生いっしょう?

一生いっしょう (いっしょう) is a whole lifetime, from start to end. As an adverb, it means "for the rest of my life".

このことは一生いっしょう忘わすれない。 — I'll never forget this as long as I live. (casual, emotional) 一生いっしょうのお願ねがい! — Please, I'll never ask for anything again! (casual, literally "the favor of my lifetime")

一生いっしょうのお願ねがい is a fun phrase: it is supposed to be the one huge favor you will ever ask, but people, especially children, use it again and again. That is part of the joke. The same kanji also appears in 一生懸命いっしょうけんめい (いっしょうけんめい), "with all your might".

How do the four compare?

Word Reading Points at Example
命いのち いのち being alive 命いのちを救すくう (save a life)
人生じんせい じんせい your life story 人生じんせいは短みじかい (life is short)
生活せいかつ せいかつ daily living 日本にほんの生活せいかつ (life in Japan)
一生いっしょう いっしょう a whole lifetime 一生いっしょう忘わすれない (never forget)

A quick test: if you can replace "life" with "survival", use 命いのち. With "journey", use 人生じんせい. With "routine", use 生活せいかつ. With "as long as I live", use 一生いっしょう.

What does 人生じんせい初はつ mean?

人生じんせい初はつ (じんせいはつ) means "the first time in my life", and it is a popular casual phrase.

人生じんせい初はつのカラオケ、楽たのしかった! — My first karaoke ever was fun! (casual, social media style) 人生じんせい初はつ、雪ゆきを見みた。 — I saw snow for the first time in my life. (casual)

It is often a little playful, a way to make a small first sound like a milestone. Our post on はじめて and 最初さいしょ explains the plain words for "first".

What are 生命せいめい and 暮くらし?

生命せいめい (せいめい) is a formal, scientific "life", and 暮くらし (くらし) is a softer word for one's way of living.

この星ほしに生命せいめいはあるのだろうか。 — Is there life on this planet? (written, scientific) 一人暮ひとりぐらしを始はじめました。 — I started living on my own. (polite, 暮くらし for lifestyle)

生命せいめい appears in 生命保険せいめいほけん (せいめいほけん, life insurance) and science fiction. 暮くらし is warmer than 生活せいかつ and is common in phrases like 一人暮ひとりぐらし (living alone) and 田舎いなか暮くらし (country life).

How is "life" used in anime?

命いのち dominates battle anime; 人生じんせい appears in reflective moments.

お前まえの命いのちは俺おれが守まもる! — I'll protect your life! (rough, a classic hero line) これが俺おれの人生じんせいだ。 — This is my life. (rough, a character accepting their path)

Games add a seventh "life": ライフ, the health bar or number of lives. ライフが残のこり1つ is "one life left".

Common mistakes

  • Saying 日本にほんの命いのち for "life in Japan". That sounds like the lifeblood of Japan. Use 日本にほんの生活せいかつ.
  • Saying 命いのちは短みじかい for "life is short". The natural phrase is 人生じんせいは短みじかい.
  • Using 生活せいかつ for the meaning of life. That is 人生じんせい (人生じんせいの意味いみ).
  • Using 一生いっしょうのお願ねがい for a small favor in a serious setting. It is a casual, slightly joking phrase.
  • Reading 一生いっしょう as いちせい. It is いっしょう.

Quick comparison

Word Reading Best English Feel
命いのち いのち life (being alive) precious, serious
人生じんせい じんせい one's life (story) reflective
生活せいかつ せいかつ daily life, living practical
一生いっしょう いっしょう lifetime emotional, emphatic
生命せいめい せいめい life (scientific) formal
暮くらし くらし way of living soft, everyday
ライフ ライフ lives (in games) casual

Practice

Try each answer yourself before opening it. Questions 2 and 3 are a pair: two "life" sentences that need different words.

1. Which word is "life" in "a doctor saved his life"?

Show answer

命いのち (いのち) — being alive. 医者いしゃが彼かれの命いのちを救すくった.

2. Say "Life is short."

Show answer

人生じんせいは短みじかい — 人生じんせい is life as a journey.

3. Ask "Have you gotten used to life in Japan?" politely.

Show answer

日本にほんの生活せいかつに慣なれましたか — 生活せいかつ is daily living. This is the pair to question 2.

4. Say "I'll never forget this as long as I live" casually.

Show answer

このことは一生いっしょう忘わすれない — 一生いっしょう means for your whole lifetime.

5. A child begs for a toy, saying it is "the favor of a lifetime". What do they say?

Show answer

一生いっしょうのお願ねがい! — usually not the last time they say it.

6. Post online that it was your first karaoke ever.

Show answer

人生じんせい初はつのカラオケ! — 人生じんせい初はつ is "first time in my life".

7. What is "living costs" in Japanese?

Show answer

生活費せいかつひ (せいかつひ) — practical daily life.

8. Say "I started living on my own" politely.

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一人暮ひとりぐらしを始はじめました — 暮くらし is a soft word for way of living.

9. What does 命いのちがけ mean?

Show answer

Risking your life — or doing something with total commitment.

10. Which word does science fiction use for "life on another planet"?

Show answer

生命せいめい (せいめい) — the formal, scientific word.

FAQ

What is the kanji for life? It depends on the meaning: 命いのち for being alive, 人生じんせい for one's life story, 生活せいかつ for daily life. The shared kanji in most of them is 生せい, "to live, to be born".

What is "life" as a tattoo? 命いのち is the most common choice, since it means life itself. Check the shapes with a Japanese speaker before committing.

How do you say "my life" as in "you are my life"? あなたは私わたしの命いのちです is dramatic but understandable. In real speech, people more often say あなたがいないと生いきていけない, "I can't live without you".

What is the meaning of 人生じんせいとは? "What is life?" or "Life is...", the start of a philosophical statement.

How do you say "daily life"? 日常生活にちじょうせいかつ (にちじょうせいかつ), or simply 日常にちじょう (にちじょう). 日常にちじょう系けい anime are slice-of-life shows.

What does 生いきる mean? To live. 生いきる is the verb; 命いのち, 人生じんせい and 生活せいかつ are the nouns that describe different sides of it.

Vocabulary from this article

Tap the block to select all of it, then copy. In Anki: File → Import, note type Basic, separator Tab — the first column becomes the front, the second the back.

命	いのち — life (being alive)
人生	じんせい — one's life (story, journey)
生活	せいかつ — daily life, living
一生	いっしょう — whole lifetime; for life
生命	せいめい — life (formal, scientific)
暮らし	くらし — way of living
命の恩人	いのちのおんじん — someone who saved your life
命がけ	いのちがけ — risking your life
人生初	じんせいはつ — first time in my life
一生のお願い	いっしょうのおねがい — the favor of a lifetime
生活費	せいかつひ — living costs
一人暮らし	ひとりぐらし — living alone
日常	にちじょう — daily life
生きる	いきる — to live

I'm Yuuki, a Japanese teacher based in Tokyo. I've taught on italki as a Top 1% teacher and watched over 1,500 anime, so most of the example sentences on this blog come from lines I've actually heard students ask about. Choosing between 命いのち, 人生じんせい and 生活せいかつ is one of those small decisions that makes a learner sound natural right away. For practice with feedback, Book a trial lesson · $13, or work through Japanese practice exercises first.

Sources: the author's own lessons and standard Japanese dictionaries.

More drills like the ones above, plus a timed JLPT-style mock test: Practice · N4 · Read something at this level: JLPT N4 stories with audio

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