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...
Don't tell me, the weapon that destroyed 
the world was still around?!
أيمكن أنّ السلاح الذي قام بتدمير العالم لا يزال موجوداً؟
¡¿El arma que destruyó 
el planeta estaba ilesa?!
Não diga que a arma que destruiu
 o mundo ainda está por aí.