Rei grew up in a pretty wealthy family compared to her classmates. Her father worked is the

owner of his own founded company for technology for electronics, while her mother is a painter.  

All classmates from Rei's class envy her for being from a well-brought up family. But everyone questions why her name is Rei.

It sounds like a guys name most of then would say. 

But for the truth of the story, Rei's parents never wanted her. They wanted their first child to be a boy.

Unluckly they say, they had her. Because Rei's mother had a weak body, she wasn't sure if she would have the

ability to have a boy after giving birth to Rei. Therefore they gave her the name, Rei. To try to raise her like a boy. 

But it was impossible, Rei had a different personality. She wasn't the type that was good at sciences, or anything related to numbers. 

They had lost hope in Rei until one day when Rei's mother came in with good news after going for a checkup at the hospital.

They were going to have a new member of the household, Rei's mother successfully had given birth

to a baby boy after going on her honeymoon vacation with her husband.Rei's new little brother. The one who was going to be

cherished the most. Rei was welcoming to her brother. She had always felt the pressure she got from being the only child.

But now she got the chance to take care of a sibling, the thought she had always dreamed of. 

Being able to be a role model for the younger one. But once her little brother got home, Rei's life changed...drastically...

On the other hand, Hiro is the youngest of his family. Born and raised by

his mother and sisters, he feels that girls are dominant in what to say in his family. His father leaving his family when he was a child,

caused Hiro's mother  to not  trust men. Knowing that Hiro is the only boy in their family, his mother tries to teach him using her

ways so that he is not influenced by his father into becoming an unresponsible man. Rei is a new transfer student at Kajiwara Gakuen. 

And is coincidentally in the same class as Rei. Being raised differently in their families,

results a mutual understanding between each other...