Yotsuya

Yotsuya lives in room #4, where he remains a total mystery to his neighbors, who know nothing about his age or job. He leads a quiet life but possesses a voyeuristic streak, frequently eavesdropping or peering through a crack in his closet that connects to Godai’s room. While he occasionally provides unproductive tutoring to Yagami, his presence usually triggers chaos. Some theorists even suggest he is actually a secret agent from another series.