first of all i must say im not the fun of student x teacher trope. its always hard for me to imagine, its more of a morality problem.
in the series their like 10-15 years apart do like.... a little bit too much, especially cause toki is mentally still a child (not only his age, but personality and acting)
despite that it was okay, i didnt really feel a real romance beetwen them, it was more of a bromance. their relationship wasnt intimate at all.
maybe if the gap was a bit smaller, i wouldnt feel confused