Otaku Douryou to Gisou Kekkon Shita Kekka, Mainichi ga Meccha Tanoshii n dakedo!

A doujinshi and a dol otaku boy's marriage begins with a fake marriage that is too much fun.

Sakizuki is a fast working designer. Even her job is chosen so that she can pursue her hobby of doujin activities. Sakizuki keeps her hobby a secret at work, but the man who suddenly proposes to her at an event is not a dol otaku (......) but her colleague, Mr. Takimoto. At work, he is an able businessman known for his cool personality, but in private, he is a full-blown otaku.

With such commonalities, there is no reason why their married life can't be fun.

(Source: MangaDex)