Mayumi Nishikino

Driven by a streak of terrible luck with men, this bitter office lady serves as the fourth resident introduced to Usa. She harbors deep resentment toward anyone experiencing romantic success, often turning to heavy drinking and nagging when feeling depressed. While she constantly seeks leverage against Sayaka by monitoring Miharu, she also takes pleasure in meddling with Ritsu and Usa's bond, secretly harboring a hidden sense of happiness for their developing relationship.