Background
In Japan, there are many millionaire families. And on top of those, there are the billionaire families. Two billionaire families have always been competing with each other. Their names are Domyouji and Hanazawa.
On the other hand, there are poor families and many orphans. Tsukushi Makino was left on the streets when she was young, along with her younger brother, Susumu. Two months later, the Hanazawa family adopted Tsukushi, and Tsukushi had to leave Susumu.
Although Tsukushi didn't want to leave her brother, she had to. Then, something unexpected happens on Tsukushi's eighteenth birthday...