@ninjazz
MC travels back in time to his high school time. he had a crush on his teacher at that time but didn't do anything about it "last time". so he used the chance of beeing back in high school to ask her to be his girlfrind.
she said "yes" and they now do lovey dovey things while keeping it a secret as good as possible.
@halloween20
Oh yeah I forgot about the actual plot. Is the fact that "his mind" comes from the future really relevant in the story ? I mean lovey dovey is nice and all but if the only danger is the discovery of their relationship then time travel is pretty much useless in the plot