From Operation Boredom :

Now that Misuzu and Masahiro are together, it seems like things couldn’t be going better for them. But can teacher and student really have a normal relationship? The odds are against them when it seems that there is trouble once again heading their way, especially when Kazuki hasn’t quite given up on destroying their relationship… can Misuzu and Masahiro’s relationship really survive through all this?

Note: This is a one volume sequel to Teachers Pet.