Sinful Love 

A collection of short stories: 1. Tsumi Koi Yashiro witnessed Maki, a classmate who is popular with the girls, with another girl who wasn't his girlfriend. Tired of her uninspiring days, she decides to become Maki's "lover," but she gradually becomes charmed by him and she can't stop herself from falling in love with him! 2. Koi ni Ochiru Made 3. Yume de Aimashou 4. Kingyou no Namida 5. Koi no Jyumon 6. Tsumi Koi Bangaihen Bonus chapter for the first story.