This is probably pretty close to reality for a lot of teacher - student relationships. You always try to do what is right according to society. In this case sensei plans to wait until her graduation to have intercourse. He was not planning on doing it before then. In this case the girl is the one who is pushy. That’s not talked about often enough.
Perhaps an important issue is hinted at in this work ... the nigh-irresistible effects of "peer pressure"; assuming that her classmates have indeed been having sex since they started high school, it's almost to be expected that Female Protag-chan doesn't want to be left out of the social group ... even if the actual "Age Of Consent" in Japan is ... wait for it ... 18 years old.
I feel a bit of empathy for "Sensei"; he was striving to do the right thing, no doubt aware that one bad move or unexpected discovery could put his career, social standing, etc., "down the tube". Yet a male in modern-day society could probably stand only so much temptation before (figuratively) snapping. Still, I'll volunteer: "Hang In There, Sensei."
That's a nice title. I like that title, really goes nicely with the Vanilla tag.
Hmm, yes, the surprise panties in the face trick...Works like a charm!
Great ending though. Indeed...If you've already done it once, what's another few hundred thousand times, yes?