I went on hiatus... (guiltily looks away JPG.)
(Also known as: "Anime Crossover: A Relaxing Retirement After Returning to the World of Detective Conan")
This is a crossover with Detective Conan, tennis, Jujutsu Kaisen, and Bungo Stray Dogs. There may be other series later, but the main setting is the world of Detective Conan.
The protagonist's real self is written in first person, while their secret identities are written in third person.
The timeline is a complete jumble, and the author has made up a ton of details.
Mizunari grew up with Akaya Kirihara, but after injuring his left hand, he transferred to Teitan Middle School in his second year. (Let's just ignore the fact that transferring would get him suspended from competition, sobbing cat JPG.) He became the tennis club's ace alongside Yuji Itadori, Ranpo Edogawa, and Asuka Shin (an original character). He led Teitan to the Kanto Tournament, where he finally got to play his brother again. This time, he would win!
(Little Mizunari is a bit like Rin-chan, but he has always made beating his brother his goal.)
Look forward to more exciting adventures from his other secret identities!
(There are lots of author-created details. For example, the U-17 tournament exists in this Prince of Tennis crossover, but let's ignore the skills that are way too unrealistic for Detective Conan. With Akaya Mizunari joining the team, Rikkai Dai remains the Kanto champions and wins the national title three years in a row. 16+3.)
Content warnings: fake character deaths, secret-identity story, some self-shipping elements, frequent revisions.