Chiaki Honda is a middle-school boy who neglects his studies. Furthermore, he smokes, and has dyed his hair a bright green. One evening at the arcade, ... a girl challenges him to a match. The girl, who straightforwardly introduces herself as Nanako Kikuchi, suggests a bet, nonchalantly wagering her body for Chiaki's watch. Chiaki is soundly defeated, and he goes home fuming.