お先に失礼いたします。 — I'll be heading out before you. (Excuse me for leaving first.) (Workplace · Greeting, Polite to Colleague, JLPT N4)

Gesture & etiquette

A brief bow (about 10-15 degrees) toward the room is appropriate. Make eye contact with your direct supervisor first before leaving — a subtle acknowledgment that you have their implicit permission to leave.

This phrase is said when leaving the office while colleagues are still working — the 「失礼」(rudeness) acknowledges you're breaking the group by leaving first. The correct response is 「お疲れ様でした」(Thank you for your hard work). Never just silently walk out in Japanese office culture.