"....they practise over a sometimes turbulent sea in stormy conditions, forced to keep an eye out not only for the Bludgers but also for planes from the Muggle airbase on a neighbouring island." (Pm)
The Mahoutokoro School Teams are comprised of students from the Mahoutokoro Wizarding School in Japan (Pm, BoP).
The Mahoutokoro School’s Quidditch teams undergo such rigorous training procedures and conditions for playing that all the members of the Japan National Team (who came third after the semi-finals of the 2014 Quidditch World Cup) and the professional Toyohashi Tengu team (Champion’s League winners), attribute their success to their time at school there (Pm).
Quidditch was introduced to Mahoutokoro School following the rescue of a group of Hogwarts students who were trying to fly around the world. While recovering, these students taught their Japanese hosts the rules and moves of the game of Quidditch. It is reported that they later regretted doing this, as the Japanese became seriously good at playing the game (Pm).
Wizarding Schools Potions Championships
Champions from Mahoutokoro School participate in the Wizarding Schools Potion Championship in order to win the potioneering prize of a golden cauldron (BoP).
Game-playing time and competition are essential components of sports training. As the members of Japanese international and professional Quidditch teams have all come from Mahoutokoro School, they would have had school Quidditch teams in order to enable this.
A Mahoutokoro team first appeared in the Wonderbook: Book of Potions, a Sony PlayStation 3 video game created from information provided by J K Rowling, where the participant becomes the Hogwarts champion competing in the Wizarding Schools Potions Championship against champions from the Mahoutokoro, Uagadou and Koldovstoretz schools.
From the Web
Writing by J.K. Rowling on the Pottermore website: Mahoutokoro
Harry Potter Wikia: Wonderbook: Book of Potions
Video walkthrough of the Book of Potions game: YouTube: Book of Potions videogame