Stories that the girl is known as a guy and the guy is known as a girl. But put them in one story.

Sulli and her sister Suzy entered a new high educated high school and Sulli promised Suzy to live an all guy this year and help Suzy with her crush problem.  

BamBam and his cousin Suga entered the same high school and BamBam disguises himself to find out more about his crush since first grade. BamBam helps him out at school.

What if They find out about eachother being disguised? What is this love game gets messed up?