Kagami is a teacher at Fujigaya Girls' Academy. Unlike a vast majority of the traditional teachers in the elite girls' school, he is very young and so has the attention of many of the students.

He is in charge of the Drama Club however does not mentor the students nor guide the club activities, though he shows up every now and then to show support for the members. The older girls in the acting troupe often make fun of him for being worse than a ghost member despite being the club's advisor.

Kagami knows Sugimoto Yasuko personally as he is engaged to her second eldest sister, Sugimoto Kazusa.

He is aware of Yasuko's feelings for him as she wrote him a letter and confessed to him. He turned her down and feels a little awkward being around her. He does not like to talk about the event, often trying to make jokes to lessen the magnamity of the situation. He later finds out on his wedding day that Sugimoto Kuri (the third eldest Sugimoto sister) also was in love with him, and he tries to laugh it off as well.

Despite winning the hearts of many girls and women, he is a very simple person with an affable demeanour, which is possibly what catches people off-guard about his personality and makes them warm up to him.

He has a habit of speaking without thinking. He off-handedly gave Yasuko the nickname "Mistress of the Library"; a name which she holds in high regard.