Worried about her son Kenji's future, Rinko is putting a lot of effort into his education, but his grades have been getting worse lately, and when he got his test back today, he got a terrible score... "I'm sending him to cram school, so maybe he's slacking off and buying manga?" Suspicious, Rinko rummages through his bag, and finds a porn magazine inside... "It looks like it feels really good... I'm interested..." Rinko has always taught her son that sex is only poison, so she makes Kenji understand with her own body by pushing him to the floor and stomping on his crotch. "How's it? It doesn't feel good, does it? Stop being interested in this sort of thing!"