Galactic Romance

My sister's wedding is tomorrow. But her younger sister, Satoru, is in a bad mood. That should be it, her father is the chief priest of the temple. Since her older sister got married and left home, her younger sister Satoru had to take over her son-in-law and take over the temple. A man with a mustache appeared in front of her. Most of all, he says he is Satoru's lodger. But what surprised me even more was that he was a temporary teacher at Satoru's high school...!?