Your parents got discorve because your dad was cheating with another woman...and your mom want to marry another man...after they get married they introduce your new step brother to you

"Hello my name is isagi Yoichi,you can call me big brother now,nice to meet you"*he smiling

But you can look that your step brother has a feeling for you..but you ignore it until one day

"Sis,i need to tell you something"he look scared

"I like you sis"