Chisato Takatsukasa, a 35-year-old novelist, has a young look that would fool anyone into thinking he is in his early twenties. His writing is influenced by his favorite, best-selling mystery author Saki Shunka, who is as mysterious as the storylines of the books she writes. Chisato is also the overprotective father of 15-year-old Riju, believing that the "friends" his son brings over on a regular basis are nothing more than predators looking for the ideal moment to contaminate his beautiful kid. As a result, Chisato will go to any length to guarantee they never return, even if it means turning to the most severe measures. But there is no one he despises more than Riju's obstinate closest buddy Shunsuke Sakaki, who just won't go away.