Sinful Sis(2014)

Honoka arrived at home with snacks, juice, and candies which are her brothers, named Hirokazu, favorite stuff. However, she noticed there has been an unexpected guest - Akasaki. She attends the same class as Hirokazu and for that matter he invited her for a study session and Honoka misunderstood her as his girlfriend. Will Hirokazu make up with his sister in a secret way while Akasaki is still in their house?