A quick reminder that Ogino is fully aware of the fact that the wife is a psycho bitch.
And Hikaru is clearly taking after his mom with the urge to abandon everything he deems bad.
ogino seems like a puritanical, sanctimonious, selfish hack, tbh. he suits the wife well. he kinda reminds me of that girlfriend from that movie 50/50; selfish and cowardly. it's not super obvious because the plot isn't really centered around him, but so far everything he's done as a teacher kinda resemble the behavior of a bad teacher who ignores the signs of a problem kid.
like you look at (ch 10 i think? the one with the parent interview) and you realize your teacher shouldn't be the one to tell the parents that their daughter has a guy friend and that that guy friend is probably screwing their daughter. like sure, she was absent, but she started class again, and you usually try to talk to the kid first and communicate with them before snitching on them to their parents.
in fact it's usually the other way around, the parents are extremely puritanical but the teachers, as counselors and advisors, recognize the parent is overstepping boundaries and that a certain degree of freedom and independence should be given to the child. they should also be more aware of domestic abuse and be willing to consult their students in private about it.
tbf, given a teacher's salary, i guess I can't say he's a "bad" teacher given that I can't really expect him to take those responsibilites seriously. personally i've had friends who (when they were kids) had good teachers that were willing to do what I described above, as well as teachers that weren't as good, but given their salary and work conditions, could really be considered average. doing what I described above is going above and beyond given teacher training and compensation, i guess.
tl;dr i think the mom and the teacher are both very selfish, and the father lacks a spine, so it all ends up being detrimental for the child.