The "Sea Diglett Bun," a famous confection limited to 30 boxes a day, can only be obtained by waiting in line. Rico and Roy get their hands on the "Sea Diglett Bun" without having to wait in line as a thank you for helping the shop owner. Meanwhile, one of the Explorers is also waiting in line at the shop, seeking the "Sea Diglett Bun"... On their way back to the Brave Asagi, Roy notices a challenge letter stuck to Hogeta's back...!?

Thanks to the Explorers' plan, the black Rayquaza has finally appeared! Rico and Roy are overwhelmed by its immense power. But if they want to convey the feelings of Terrapagos, and their own feelings, now is the time— The two have had so many encounters and experiences since the day they set out on their adventure with their Pokémon... Now, the battle against Rayquaza begins, where they will put everything they've learned into it!