The happiness of my favorite is my happiness―― Only my favorite can win!!! Rize, a druggist who was a marginal otaku in her previous life,One day, I found my favorite character, Mair, the son of a duke, collapsed on the street, and realized that this world was a world of maiden games!And while taking care of him, who doesn't seem happy at all, she makes a decision. "I will make Mare the happiest in the world!!"As things turn out, I start living with my Oshi, but... my Oshi is so precious that I can't hold my heart!What's more, I, a mobster, have become Mare-sama's temporary fiancée!?A love comedy about a girl who loves her boyfriend with all her might and is overwhelmed by his preciousness, only to be surrounded by him!