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...
leading to one of those "end 
of civilization" scenarios.
مما قاد بهم إلى سيناريو نهاية الحضارات الشهير ذاك
y terminaron en el típico 
escenario posapocalíptico.
o que levou a situações de fim
 da civilização e coisa assim.