Recap of the first 12 episodes of Okoshiyasu, Chitose-chan.

With the arrival of the U-17 World Cup, youth tennis teams from all around the world gather in Melbourne, Australia to determine which is the best. With nine-time champion Germany vying to defend their title once more, and powerhouse nations—Switzerland, France, and the United States—determined to make things interesting, the road to victory is perilous. Although Japan is sitting at the bottom of the rankings, the addition of the nation's strongest middle school players has reinvigorated their chances at winning. Captained by the ruthless Houou Byoudouin, Japan is ready to show the world what they are capable of. However, before the real competition starts, the teams will have a chance to prove their strength through exhibition matches. As luck would have it, Japan is slated to face off against defending champion Germany—a match they are likely to lose. To make matters worse, old allies have suddenly reappeared as sworn enemies. Before Team Japan crumbles under the pressure of the international stage, they must rise from the ashes and claim the title for themselves.

Nagi Umino and Erika Amano, a studious high school student and a social media star, had nothing that linked them together—until they found out they were swapped at birth. When the sudden news is revealed to both of their families, their parents quickly devise a proposition with neither Nagi's nor Erika's knowledge: in order to restore them both to their rightful families and ensure everyone's happiness, the two should get engaged. When informed of this, Nagi and Erika are quick to reject the absurd plan, refusing to go along with their parents' wishes. But, with neither party willing to back down, only time can tell where their relationship will go.

After the capture, Hajime was worried about the farewell to Miu that would occur when the trip resumed. Hajime and his friends were talking about "The Seven Great Legends of Elysen" as a memory before they left for the trip, but all of them were missed. However, in the final seventh adventure, he encounters a mysterious giant creature and is blown into the world of a devastated city! Hajime, who started to search for the stray Mew, fulfills a miraculous encounter there.