夜ふかし（よふかし、yofukashi）
- staying up late

The Japanese word 夜ふかし (よふかし) means staying up late, or staying up past one's usual bedtime. It implies a conscious decision to delay sleep, often for leisure or because of a specific task. It suggests a later night than is typical. The word focuses on the act of being awake and active later than usual rather than simply the lack of sleep itself. The literal translation is "night staying."

⚫︎今日は夜ふかしして、映画を観ようと思います。 Translation: I plan to stay up late tonight and watch a movie. ⚫︎最近、夜ふかしが続いて、疲れがとれません。 Translation: Lately, I've been staying up late, and I can't shake off the fatigue. ⚫︎彼はいつも夜ふかしして勉強しています。 Translation: He always stays up late studying.

This word is appropriate in many situations, whether describing your own actions or those of others. It can be used casually with friends and family. It is best to avoid it in extremely formal situations or in contexts where you need to be very polite. For example, talking about 夜ふかし with a boss is acceptable, but you might want to phrase it more delicately. You would use it to talk about how you stay up late for fun, work, or other activities.

夜ふかし (よふかし) is usually written in hiragana. Although the kanji would be 夜更かし, it is more commonly written in hiragana. 夜 means "night," and ふかし is a noun derived from the verb 更かす (fukasu) which means "to advance (the night)" or "to stay up late". The okurigana (hiragana attached to the kanji) is ふかし or ふか. Other ways to write this word: Kanji: 夜更かし

⚫︎寝不足 (ねぶそく) - Lack of sleep ⚫︎遅くまで起きている (おそくまでおきている) - Staying up late ⚫︎徹夜 (てつや) - Staying up all night. This is a stronger form of 夜ふかし.

⚫︎早寝 (はやね) - Going to bed early ⚫︎早起き (はやおき) - Waking up early ⚫︎早く寝る (はやくねる) - To go to bed early

昨日は課題が終わらず、ついつい夜ふかしをしてしまった。 ・Translation: I didn't finish my homework yesterday, and I ended up staying up late. ・Explanation: This sentence explains a situation where someone stayed up late because of unfinished homework.

週末は、夜ふかししてゲームをするのが好きです。 ・Translation: I like staying up late and playing games on the weekends. ・Explanation: This sentence describes enjoying 夜ふかし for recreational purposes, specifically playing games on weekends.

The word is formed from 夜 (yo), meaning "night," and the verb 更かす (fukasu) which means "to advance (the night)" or "to stay up late". The shift to the noun form, ふかし, creates the compound word 夜ふかし, which directly translates to "night staying" or the act of staying up later than usual into the night.