Akira wants to be wife really badly but Sensei don't want to meddle into Sensei/Student relationship. I hope Akira's mom found out who Akira likes and kept pushing more. It would be much better if the head education is a succubus too and gave thumbs up to Sensei.
Some people may say "Teacher is 'grooming' children", but this is one of case where, "The Teacher/Sensei is being GROOMED by student" with Blue Archive Sensei nodding in the background while having his nonexistence human right violated again.