Otakon no Susume!

Otaku x Otaku = The Best Fake-Married Life! Ryota Shinonome, an aspiring manga artist, and Akemi Oda, an office lady and doujinshi artist, were fed up with the pressure from their surroundings to "fall in love" and "get married." They meet through a dating agency and decide to get registered immediately due to their common interests. Their fake marriage was supposed to be just a cover for their otaku activities, but…! (Source: Kadokawa, translated)