Link: https://rtain.jp/rtaij/nintendo/

Google translation of the page:

Notice regarding the use of Nintendo Co., Ltd. games in RTA in Japan

2025-08-04

We would like to explain how we have come to use games for which Nintendo Co., Ltd. holds the copyright (hereinafter referred to as "Nintendo games") in RTA in Japan, and why Nintendo games are not being used in RTA in Japan Summer 2025, as well as our future actions.

RTA in Japan has previously used Nintendo games, but on June 13, 2025, Nintendo Co., Ltd. pointed out that "the use of Nintendo games by a corporation requires prior permission," and that our previous use "was without prior permission and constituted unauthorized use."
RTA in Japan wishes to continue using Nintendo games, and has begun discussions with Nintendo Co., Ltd. regarding permission.

As of now, the decision has been made that RTA in Japan will submit individual licensing applications to Nintendo Co., Ltd. for each event and game. However,
for RTA in Japan Summer 2025, we were unable to clearly determine how to handle this at the time the participating games were announced, so we have decided not to use Nintendo games.

For events held at RTA in Japan after RTA in Japan Summer 2025, it is expected that permission will be submitted in advance to Nintendo Co., Ltd. and that permission will be granted before the event can be used.

As a result of this, it is expected that the RTA in Japan game application guidelines and application requirements will change, and we will notify you as soon as the details have been decided.

We would also like to apologize to those who submitted games that were affected by this issue to RTA in Japan Summer 2025.

RTA in Japan