Initially, Miyake entered a physical relationship with Oohashi as a stand-in for Takeda, Oohashi's crush. However, over time, they started living together and became more like a couple. Oohashi, who is anxious and tends to be overprotective, has grown increasingly possessive of Miyake—enough to ease Miyake’s own anxieties. Meanwhile, Miyake continues to update his “Oohashi Observation Notebook” in proportion to the time they spend together. (Source: Ichijinsha, translated)
The time is Taisho. A half-vampire girl, Meiko, has lost her parents and is left alone on her own. She is shunned and hated by the villagers, and is eventually locked up in a dark cell... She is saved by the army commander Shindo Keiji. Whenever she comes into contact with his enveloping kindness, Meiko gradually develops a special feeling for him... However, as her feelings grow stronger, the half-vampire's urge to "seek the blood of the one she loves" becomes uncontrollable...! I'll change everything about you... The Cinderella story of a half-vampire girl and a gentleman soldier begins!
He is capricious, sometimes saying sweet things and other times being cold. With the help of her cat, she is finally going to conquer the boy who always teases her... (Source: Sho-Comi, translated)