Looking for a manga ...

Hey guys,
I'm looking for a manga and I hope you could help me?!
There are two couples in this manga. It's set in a primary school!
The first couple is a pair of teachers.
One of them is always jealous of his co-worker because he is a more reliable teacher.
The second couple is a Teacher - parent pair.
The teacher was a hoodlum in his past but becomes very strict and reliable teacher who scolds the very young father who isn't a perfect parent.
Hope you can help me out?
Thank you very much in advance