Sensei!

I haven't read this cause these days my internet connection getting so slow. My sister is 18 this year and her boyfriend is 26. They have been together for 3 and a half year so I don't think their relationship was for fun. Ah and my math teacher is currently dating with my physics teach. Still they decided not to remarry since both of them have children from their previous married and they're no longer very young. But I feel good somehow that in the end everything turned out right. I was a little sad for him when I heard what had happened.
I wonder if my english is ok. I'm lazy to check my grammar.

Well, I won't disagree with you in general. There are reasons for the rules against student/teacher relationships; the power imbalance is huge. And there are serious problems with big age differences. That said, when I was 24 I went out for a while with a girl who was 16, and it was good for both of us. Now I'm married to a woman who I love a whole lot who is quite a few years older than I am; we've been together 20 years. And that age gap causes tensions sometimes, but it's worth it because it's her.
Most social rules have exceptions; life is messy. But yeah, almost all the time student-teacher relationships are a terrible idea in reality. And almost all the time, student-teacher relationship shoujo manga are about a daydream--the allure of forbidden love with a hot mature man, yadda yadda--not about a reality. Kind of like most of the bro-sis incest manga. Which makes them fun but fluffy. But Sensei! really feels like a story about that rare exception, about two people who really fit despite differences in age and role. I'm very fond of it.

@Purple Library Guy You always give this looooooong review of the manga. So here more.
In my opinion I don't support teacher-student relationship. My math teacher at my high school married his student when he was really young. He has a really hilarious sense of humor( even I've to admit this). She fell in love with him .Usually teachers don't marry their student but he did. It caused such a big disturbance in the school those days. After they had 2 child. I heard she ran away to another man. And my teacher was in utter despair......(is what I heard )
Basically the relationship between teacher and student isn't meant to be taken seriously. Especially female student, I think they're young and still can't separate love and like. After they grow up, they usually find their partner boring. Like "I'm still young and a bright future is ahead of me, why do I have to be stuck with this old man?". But this is my opinion, they said love is not restricted by age.

This is a very good manga. Earlier chapters can be found in other places fairly easily.
There are a lot of sensei x student shoujo out there. This is probably the best IMO. It has good characterization, good realism, good secondary characters, good pace (not too fast, not too slow), strong but not melodramatic emotion. The main characters are individual; the female lead is not a typical shoujo heroine, while the teacher is not a bishounen or any other manga stereotype I recognize. He feels like a teacher and an adult rather than the hot boy next door somehow transplanted into a teaching job. And the two of them have chemistry. He doesn't feel like the type who'd go around falling for his students, and yet I can see why he falls for her in specific--it's not just some wish-fulfillment dangerous liaison fantasy, it's about those two people. If you like good shoujo romance, this is one not to miss.

Long ago, whoever else was working on it dropped it and I feared that would be that. So I'm very happy that more recently the people involved in "I Love Sensei!" have adopted this manga and are continuing the scanlation and have put it up here. Thanks!