...I guess since she's the heroine, but he can just show that after she hit him he changed after they meet at the academy, he's fine with recreating the story of the original with her at this point in time? So that the plot of the original follows its intended path for her, if nothing else?
IDK, probably just his excuse to get beaten by her. Then again, he played into the evil mastermind's plan by getting into the trap willingly and all, so that he wouldn't raise suspicion - and that also was happening "similarly" as it was supposed to...
I guess I'll believe him when he says he wants to keep at least the rough extent of the events covered in the game's prelude the same to keep future, more important branching events the same, but his idea is to change himself so that he doesn't end up dead during what would be the actual gameplay.