OniAi(2012)

OniAi

Akiko is thrilled to be reuniting with Akito, the handsome older brother she hasn’t seen in years! In fact, she might be a little too excited. This pint-sized cutie has a big brother complex, and she’s not interested in sharing his attention. Unfortunately for little sister, she and Akito won’t be living alone: three gorgeous girls from the student council will be along for the ride!

(Source: Crunchyroll)