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...
the easiest way is not letting 
the PTA into this room at all.
الطريقة الأسهل هي عدم فتح المجال لرابطة الآباء والمعلّمين للدخول في المقام الأوّل
lo mejor es no dejar entrar 
a la APA a tu cuarto.
o jeito mais fácil é não deixar
 que a Associação entre.