Ep. 5: Kagerou of the Spring
Ririchiyo wants to write a letter of apology to Soushi, but she hesitates trying to find the right notepad to write on. Ririchiyo has been getting disturbing text messages from a block number, shrugging them off until they become more frequent and threatening. While Ririchiyo is walking back from the store alone at night, Soushi finds her and expresses his worry for her. Soon after, Kagerou Shoukiin, the one responsible for sending the text messages, appears out of the blue. As he is also a childhood friend of most of the other male residents, Kagerou gives all the tenants and agents various "bondage items" as gifts. He also mentions that Soushi had formerly served under him, catching Ririchyo off guard. After he then claims to be engaged to Ririchiyo, she remembers exchanging letters with him when she was young. (Source: Wikipedia)