Well, I read a manga, and I wanted to read it today, but I forgot the title, and i have been searching for that whole the day..

A girl woke up his brother (they were not blood-siblings) and then she went to school. She said she always thought about him as a cute puppy, and she thinks he's not interested in girls. On her way to school she saw his bag on a corner then she saw him with hanging and flirting with some girls. She asked somehing like that: What are you doing? You're not interested in girls, are you? Why are you hanging with these girls? He answered: If you don't want me to do it with them, let me do it with you.

I can't remember more. Pleeease if someone knows the title then reply me.^-^