There's something about changing the past that I find implicitly horrifying.
Kaede seems to be happy though, even if this isn't the same Minami she once knew.
What if Kaede, in her efforts to help Minami become a full fledged teacher, ends up making it so that Minami never had to take tutoring on the side? If that happens, the two never would never have been able to meet, thus removing Kaede's motive to time travel... This is why I despise time tomfoolery