Translation guide
The English phrase 'come of age' refers to reaching legal adulthood or maturity. In Japanese, this is most commonly expressed with the noun 成人 (seijin) or the verb phrase 成人する (seijin suru). The concept is strongly tied to the legal age of 18 (as of 2022) and the cultural celebration 成人式 (seijin-shiki).
To become a legal adult, typically at age 18 or 20 depending on context.
Noun meaning 'adult' or 'adulthood'. Often used in the phrase 成人になる (become an adult).
彼は今年成人になった。
He came of age this year.
Verb phrase meaning 'to reach adulthood'. More formal than 成人になる.
日本では18歳で成人する。
In Japan, you come of age at 18.
Common colloquial way to say 'become an adult'.
成人になったら、お酒が飲める。
Once you come of age, you can drink alcohol.
To take part in the ceremony or celebration marking adulthood.
Literally 'to welcome the Coming of Age ceremony'. Used when someone participates in the event.
今年、成人式を迎える若者が多い。
Many young people are coming of age this year.
More direct: 'attend the Coming of Age ceremony'.
彼女は成人式に出席するために帰省した。
She returned home to attend her Coming of Age ceremony.
To reach a stage of full development, often used for art, movements, or personal growth.
Means 'to mature' or 'to ripen'. Used for people, ideas, or fields.
彼の芸術は最近成熟してきた。
His art has come of age recently.
Literally 'become a full-fledged person'. Implies reaching a level of competence or independence.
彼は修行を終えて、一人前の職人になった。
He completed his training and came of age as a craftsman.
成人 (seijin) specifically means a legal adult, while 大人 (otona) is a more general term for a grown-up. Use 成人 for legal contexts and 大人 for everyday maturity.
成人は18歳以上です。
Adults (legally) are 18 and over.
大人になったら、何になりたい？
What do you want to be when you grow up?
The legal age of adulthood in Japan was lowered from 20 to 18 on April 1, 2022. However, some activities like drinking and smoking still require age 20. Be aware of context when discussing coming of age.
彼女は来月成人します。
She will come of age next month.
その小説は戦後日本で成人する少年の話です。
The novel is about a boy coming of age in postwar Japan.