Rin Koyama

She is a bassist who asks Hatono to form a band, La Cittadella (and later Heartbreak after their initial disbandment). After secretly watching her sing, Rin becomes obsessed with Hatono's vocals, to the point of worshiping her as her "god". She pulls numerous schemes in order to form a new band with the perfect members and Hatono as frontwoman. Although she often looks like the guru of the informal "Hatano cult", Rin shows genuine affection and concern for her and the other members of the group in critical moments. She uses a sunburst Fender Jazz Bass.

Rin, as an exceptional manipulator, always keeps her cards close to her chest and rarely expresses her true intentions until after she's already succeeded at whatever her goal is. She acts unfailingly polite, even when she secretly has deep disdain for whomever she's talking to. Rin is able to read most other people like a book, knowing what they'll do if given the right situation and stimulus.