Originally just a regular sports anime fan on Earth, he suddenly finds himself transmigrated into an anime world. Awakening the template of Akashi Seijuro, he initially believes he has entered the world of Kuroko no Basuke.

But it isn’t until he hears the name of the man standing at the very peak of the world that he realizes—this is the realm of killer tennis!

He acquires Fudomine Middle School, establishes a brand-new tennis club, and gathers all the top-tier players from the junior high world. Using the power of the template system, he accelerates each player’s growth.

Through that, he leads them to a three-time national championship victory and onto the U-17 world stage

Accidentally traveling to the world of the comic version of Prince of Tennis caused a change in the world line.

The champion Rikkai University completed an unprecedented three consecutive national championships.

Kunimitsu Tezuka did not let injury ruin his three-year tennis career.

Echizen Ryoma has completely turned evil, and he firmly believes in staying in the American team and waiting for an opportunity to avenge Byodoin Phoenix.

...

The person who triggered this butterfly effect was a Quincy who escaped the large-scale [Sacred] punishment when Yhwach awakened and fled here.