Ohsugi is crossing the Despair Event Horizon because Sonoda isn't around anymore. What does he do? He tries to give Gentaro detention, for no reason other than because he wants some "company". Huh. Gentaro gets a bit shocked by this...And so do the other students.
Ohsugi: Come with me to the staff lounge. You're my conversation buddy now.
Gentaro: Why me?
Ohsugi: I'm lonely!
(Gentaro stares at Ohsugi while he brings out a photo of himself with Sonoda attached by tape)
Ohsugi: Sonoda-sensei! My beloved...How long is she going to be sick?