Karesen

is a japanese manga series written by Aoki Nagiko. It began serialisation in the July 2019 issue of Manga Time Kirara Forward.

The series was released under 3 volumes from February 2020 to January 2021.

Synopsis
Mashiro Wakana is a high school girl with a thing for older men. She fell in love with Sakai (53 years old), the nutritionist at her school, and got up the courage to confess. Sakai-san seemed like a suave gentleman to her, but he's actually a hard-core otaku without any experience in romance!

(Source: MU)