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...
I'd be done for if anyone 
saw my room like this!
إن رأى أحدهم غرفتي هكذا
¡Si me ven así, será mi fin!
Se virem o meu quarto
 assim, será o meu fim!