Mitsuki is Izumi's younger sister, by one year, and is hired by Yoshitaka along with Izumi. By using photographs from Yoshitaka's media archive, she signs Izumi up for a 'Net Idol' website, which later, with revenue from Izumi's performances, helps Izumi pay off her debt. Mitsuki herself actually becomes very rich because of Izumi's popularity. Mitsuki always (when under Yoshitaka's contract) refers to Yoshitaka as Goshujin-sama or 'Master'. She even has her own fan club from her own school and other schools as well. She frequently comes up with (weird) competitions whenever two characters have divided opinions, most of the competitions ends up with Pochi playing some kind of key role that results in a bizarre conclusion, she seemes to favor Yoshitaka during these competitions and usually requires Izumi (albeit unwillingly) to compete. She loves the maid uniforms while as Izumi thinks they're way too revealing. Mitsuki even sang a song at a festival entitled "I'm a cute maid at a perverts house!" (Source: Wikipedia)