既読

• Reading: きどく
• Romaji: kidoku
• Kanji breakdown: 既 (already) + 読 (read) → already read
• Pronunciation: /ki.do.ku/

Meaning

Read receipt — the indicator showing that a message has been read, especially on LINE. Also used broadly to mean 'I saw it but didn't reply.'

While 既読 literally means 'already read,' it gained immense cultural significance through LINE's read receipt feature. The dreaded 既読スルー (reading but not replying) became a major source of social anxiety, especially among young people. The word now extends beyond LINE to describe any situation where someone has clearly seen a message but chosen not to respond.

Examples

1. 既読ついてるのに返事こないんだけど、怒ってるのかな。 It shows they've read it but they haven't replied — I wonder if they're mad.
2. 既読スルーされると地味にへこむよね。 Getting left on read is low-key depressing, right?
3. 大事な話だから既読つけたらすぐ返してね。 This is important, so reply as soon as you see it, okay?

Usage Guide

Context: messaging, LINE, social media, friends

Tone: anxious, matter-of-fact

Do Say

• 既読ついてるよね？なんで返さないの？ (You've read it, right? Why aren't you replying?)
• ごめん、既読つけたまま忘れてた。 (Sorry, I saw it but forgot to reply.)

Don't Say

• 目上の人に「既読スルーしないでください」は失礼 (Telling a superior 'don't leave me on read' is rude)

Common Mistakes

• Not understanding the social weight of 既読 in Japanese culture — being left on read is taken more seriously than in many Western cultures
• Confusing 既読 with 未読 (midoku, unread)

Origin & History

既読 (already read) existed in Japanese before messaging apps, but gained its modern cultural weight when LINE introduced read receipts (既読機能) in 2011. The anxiety around 既読スルー became a widely discussed social phenomenon.

Cultural Context

Era: 2011, with LINE's read receipt feature

Generation: All ages (especially teens to 30s)

Social background: Universal

Regional notes: Used across all of Japan. LINE is the dominant messaging app in Japan, making 既読 one of the most culturally significant tech terms.