During with 〜うちに
Grammar: Time and Sequence » 〜うちに
〜うちに is used to refer to a period of time. The period of time is represented by the modifier in front of うちに. Often 〜うちに is used when taking advantage of an opportunity.
Further Reading
- How to use うちに & うちは (maggiesensei.com)
Related Grammar
- While with うちは
- Used when contrasting with another period of time.
- During the same time with 間に
- Used when one action takes place during another.
- Concurrent events with ながら
Examples
Decision made during the day yesterday with 〜うちに

Yukari and her friends have a miscommunication on whether they’ll change from their summer uniforms to their winter uniforms yet. The decision is finalized just in time, as the following day is even colder.
- ユカリ:
- 「昨日のうちに衣替えしておいて良かった。」
- “I'm glad we (took the opportunity and) settled our uniform change (during) yesterday.”
Save Rei while it's foggy with 〜うちに

Jadeite captures the priestess Rei. Ami uses an ability to fill the area with fog, giving Usagi a chance to act.
- 亜美:
- 「うさぎちゃん!霧が出てるうちにレイちゃんを助けて!」
- “Usagi! (Take the opportunity to) rescue Rei while it's foggy!”
While I didn't see you with 〜うちに

Jumbo arrives to help Yotsuba and her father move into their new home.
- よつば:
- 「しばらく見ないうちにまた大きくなった!」
- “You've grown bigger since I last saw you!”
- Literal: “During the time I didn't see you, you've gotten bigger!”
- ジャンボ:
- 「お?どこでおぼえたそのセリフ」
- “Oh? Where'd you pick up that line?”