Dororo x Koyuki - pretend marriage is a 2020 Sgt. Frog Little Mermaid parody fanfic written by RFART419 featuring Dororo cosplaying as Ariel the mermaid & Koyuki cosplaying as Prince Eric while pretending to get married in a beach.
This Little Mermaid parody fanfic is now available on Fanfiction.net: https://www.fanfiction.net/s/13606995/1/Dororo-x-Koyuki-pretend-marriage-Little-Mermaid-parody-og