Kimajime Danna-sana no Kakushi Kirenai Jouyoku Dekiai - Gisou Kekkon kara Amai Koi wo Hajimemasu

The summer of my freshman year of college---18 years old, I married my first love, my brother's best friend.

Shiori, who lost her family in an accident, married her brother's best friend, Takumi Nakazawa under false pretenses, but she still had feelings for him. On their third wedding anniversary, just as Shiori makes up her mind to tell Takumi how she feels about him, Takumi declares, "Let's get a divorce. Shiori tries to avoid divorce, but she fails at every attempt, and even witnesses her husband alone with a woman...?