Kingyoya-san no Karisome Fuufu

The story of a contract marriage set in an old-fashioned goldfish shop.

Asahi and Nana are newlyweds who run a goldfish shop. At first glance, they seem to be a normal couple, but in fact, they are a contractual couple who got married because of their mutual interests! They are not true husband and wive, let alone lovers. And yet...

[I'm sorry. I know this is our first time meeting, but will you marry me?]

https://www.cmoa.jp/title/277575/