夜更かし

• Reading: よふかし
• Romaji: yofukashi
• Kanji breakdown: 夜 (yo/yoru) — night; 更かし (fukashi) — staying late, deepening the night
• Pronunciation: /jo.ɸɯ.ka.ɕi/

Meaning

Staying up late; keeping late hours; sitting up into the night beyond one's usual bedtime.

A noun (often used with する) describing the habit or act of staying up later than usual or than is considered healthy. Unlike 徹夜 (pulling an all-nighter, typically for work or study), 夜更かし carries a slightly indulgent, leisure-driven nuance — watching films, reading, or simply losing track of time. It appears commonly in casual conversation and health-related discussions.

Examples

1. 休日前は夜更かしして好きな映画を何本も見てしまう。 Before days off, I end up staying up late watching several of my favourite films.
2. 夜更かしが続いたせいで、最近ずっと体がだるい。 After a run of late nights, I've been feeling lethargic all the time lately.
3. 子供の頃、親に内緒で夜更かしして漫画を読むのが楽しみだった。 As a child, secretly staying up late to read manga without my parents knowing was one of my little pleasures.

Usage Guide

Context: daily life, health, habits, leisure

Tone: slightly indulgent

Origin & History

Compound of 夜 (yo/yoru, night) and 更かし (fukashi, deepening/staying late into). 更 (kou/fuke) means to deepen or advance through the night — as in 夜が更ける (the night grows late).

Cultural Context

Era: Modern

Generation: All ages

Social background: Universal