Why does he keep calling him 'teach' ?! Σ(っ°Д °;)っ

habit i guess! if i saw my sensei again even after i graduated i would still call him sensei.

I know buuutttt after everything they have done.... I just think it may be time for some pet names (=・ω・=)

hehehhe that's true! maybe after some time they'll be comfortable enough for that... i really want to see it though! hope the story doesn't end too soon :3