Haruna Aizawa thinks that school life is just like a monkey mountain--all the monkeys form cliques, get into fights, and get back together again. The school that she just transferred to is no exception. There's even a boy called Macharu Yamashita who reminds her of a baby monkey!

Haruna and Macharu head off to the amusement park for their official first date! But how romantic is the date going to turn out with scary roller coasters, guys hitting on Haruna, and even rowdy classmates popping up?