Kamiki Kyoudai Okotowari

High-school freshman Iroha's life is about to change. Her mother just got remarried, and they're both moving in with her new partner and his sons. The elder son is really hot, but he's far from normal ? and together with his cute younger brother, she's now stuck with them both morning, noon, and night! The mean elder brother and Iroha just can't see eye to eye, and as the distance between all three of them decreases, cohabitation has never been so heart-poundingly exciting!

(Source: Kodansha USA)