Ajinomoto Stadium is a 48,000-seat multipurpose stadium in Chofu City, Tokyo, used for international soccer and rugby tournaments and live concerts.
Note that this stadium is different from the Japan National Stadium in Shinjuku City, which was used as the main stadium for the Olympics.

Ajinomoto Stadium hosted soccer, Rugby sevens, and Modern Pentathlon matches during the Tokyo 2020 Olympic Games, and is also the venue for the Rugby World Cup 2019.

About the name Ajinomoto Stadium

Ajinomoto Stadium, known to the Japanese as “Ajista”, is officially known as “Tokyo Stadium”.
The name “Ajinomoto” is derived from the fact that Ajinomoto Co., Inc., a Japanese food company, holds the naming rights to the stadium. Ajinomoto is the company that sold the frozen gyoza (dumplings) served in the cafeteria at the athlete’s village during the Tokyo 2020 Olympic and Paralympic Games.

J-League (Japan’s Professional Football (Soccer) League) and Ajinomoto Stadium

Ajinomoto Stadium is the home stadium of two Japanese professional football (soccer) league clubs, F.C. TOKYO and Tokyo Verdy.

F.C. TOKYO has started online ticket sales in English for foreigners from May 22, 2023, making it easier to purchase tickets than before.
If you are interested in the J-League and stadium food, why not visit?

ENGLISH-LANGUAGE TICKET INFORMATION
https://www.fctokyo.co.jp/news/14764