This is the R18 version which includes adult sex scenes! Based on a josei romance smut manga by Torai Shiguma.

The two are female teacher and her student... but they are engaged!?

Nano is a popular teacher who is admired by students. Only Souji, a male student, gives her trouble. One day, someone she knows introduced her for an arranged marriage. Nano is worried at first, but later becomes frank with the man who she meets and is in a good mood. Later, she realized that he is Souji who disguised as someone else! Even though she rejects the arranged marriage, Souji still comes to pursuit her.

Will Nano, the serious teacher, be able to reject Souji's love...?