Joonha is a normal, healthy boy of sixteen who's cruised through life without too many problems. So imagine his surprise when one day a routine trip to the bathroom reveals that he's not normal at all! With a shriek, he discovers he's suddenly missing...well, something he never thought he could live without. The truth is, his family is abnormal in the weirdest possible way: after puberty, their bodies undergo a mutation that converts them into the opposite sex! Now Joonha has to leave behind his life as a boy and live as a girl - in the middle of high school.