The stage is Tsukiji*
One day three 2nd year middle school students; Kazuki Yasaka, Tooi Kuji and Enta Jinai meet a mysterious human-like life form known as “Company President”, forcibly have their shirikodama stolen and get made into sushi chefs.
“If you want to return to your former middle schooler selves, grasp** in “that way” and bring the tuna shirikodama”.
Is what the Company President told the trio. Can the boys make rice balls*** and steal the tuna shirikodama?!
At the same time at the Asakusa Kaminarimon shop where Reo Niiboshi and Mabu Akutsu work something is about to happen.
*The Tsukiji market located in Tokyo is the largest fish market in the world
**/***The kanji used was 握る (nigiru). It can mean both “to grasp” or “to make” for example nigirisushi and rice balls. How punny of them!