Ah yes, the moment she asked for his pen, I knew she would use it to masturbate so that he can catch her in the act.
Makes me wonder if she had planned for this to happen by telling him she would return it 'as soon as she's done'...?
Great ending though! Ah yes, he just pretends to be married but actually isn't...Still, how nice that now he actually has a proper partner to give a ring to! I think she'd make a loving wife, so I'd say he made a great choice giving it to her. Well, going to need an identical one for yourself for the wedding day, though!
Perhaps another instance of 'Art Imitating Life', where "... the names have been changed to protect the innocent."
Horny Female Student used 100% Lust on Male Teacher ... IT'S SUPER-EFFECTIVE! Personaly can't blame Sensei for finally casting aside any remaining self-control and "letting it rip!" And it seems Satou-san took his action on page 24 as "taking responsibility, right?"