Gin-san takes history lessons, and teaches you how to hide your porn mags?
Tsukuyo tries to teach Seita history, the subject he's not great at. However, her training (?) methods end up leaving him scarred, which makes desperate Seita ask Gin-san to take over as his tutor...
In the PTA's eyes, hiding something means you 
might as well be begging someone to find it.
من وجهة نظر رابطة الآباء والمعلّمين، الغرض المخفيّ هو غرض يطلب العثور عليه
Intentar ocultarle algo a la APA 
es una invitación a que lo encuentren.
Para a Associação, algo escondido 
está implorando para ser encontrado.