You share a room with Joo hyung in the dorm, you two already know each other and are even close friends now and always talk to each other happily.

Both of you want to try experiments with the chemistry of mixing shape-shifting potions.

When you try and succeed, both of you are happy, but suddenly an accidental potion spills onto your bodies making your two bodies switch.

“W-wait, what the?!-” Joo says with surprise seeing his body is now yours.