Wataru, a 3rd year student, has to do the cleaning at school in order to get enough credits to graduate. His partner in cleaning is Yugo, a 1st year student who tends to be absent at school. Yugo's arrogant attitude piques Wataru's interest since he sees in Yugo his childhood friend and, as a result, Wataru feels it's his duty to take care of him.
But Yugo hides a secret...