Rin Rin Side!!

Sakura Oto, an unpopular member of an idol group finds herself in between two idols from the same group who have... interesting personalities. Beginning with Rin-chan, the newest and most popular addition to the group. While she is the most popular girl in the group, she is also Sakura's number one fan. Next is Ritsuko-san, a free-spirit and complete flirt who is just as popular as Rin-chan. With all of them living together, Sakura will have to deal with cohabitating with a superfan and womanizer, all while trying to figure out her own insecurities as an idol.

(Source: EManga)