The Great Monkey Baseball
As the castaways swim in a mysterious sinkhole, they seem to be momentarily taken back home. Cap invites Nagara to practice baseball with him, leading to him telling about the Monkey League, and how its star pitcher, Blue, missed out on a perfect game.
Aired 06/08/2021EP 4 - The Great Monkey Baseball

2021
Sonny Boy
It’s an ordinary summer vacation...except for the fact that Nagara’s high school has mysteriously drifted into another dimension. As the students begin to develop strange new powers, will they work together to survive the alien environment and find a way home, or will their newly formed factions and rivalries turn on each other?
(Source: Funimation)
Note: The first episode received an advance release on YouTube on June 19, 2021. The regular TV broadcast started on July 16, 2021.