Momotaro Mikoshiba

御子柴百太郎 御子柴 百太郎（みこしば ももたろう）

He appears from episode 2 of season 2. He is a first-year student at Samezuka Academy and the younger brother of Seijuro Mikoshiba. He is 172 cm tall, weighs 59 kg, and was born on December 6th under the Sagittarius sign. He has a cheerful and lively personality. Like his brother, he falls in love easily and is fond of Gou, often making advances towards her, but Gou mistakenly calls him "Kintaro-kun," and Amakata-sensei mistakenly calls him "Urashima-kun." His hobby is collecting stag beetles, which he names "Pyunsuke," "Rinrinmaru," and "Lovejiro." His favorite food is cheeseburgers, and he dislikes bitter foods like bitter melon. His favorite saying is "Even a kappa can drown," and his favorite stone is basalt. Initially, he had no intention of joining the swim club, but he joined after swimming a relay with Rin and the others. His specialty is backstroke, characterized by a smooth underwater dolphin kick. He has won several middle school competitions and earned the nickname "Sea Otter of the Sea of Japan." Although he was not originally a relay member, he was selected just before the prefectural tournament due to his individual backstroke results. Like Nitori, he supported Sosuke, who had injured his shoulder, in participating. His image is that of a sea otter.

Momotaro Mikoshiba

御子柴百太郎 御子柴 百太郎（みこしば ももたろう）

He appears from episode 2 of season 2. He is a first-year student at Samezuka Academy and the younger brother of Seijuro Mikoshiba. He is 172 cm tall, weighs 59 kg, and was born on December 6th under the Sagittarius sign. He has a cheerful and lively personality. Like his brother, he falls in love easily and is fond of Gou, often making advances towards her, but Gou mistakenly calls him "Kintaro-kun," and Amakata-sensei mistakenly calls him "Urashima-kun." His hobby is collecting stag beetles, which he names "Pyunsuke," "Rinrinmaru," and "Lovejiro." His favorite food is cheeseburgers, and he dislikes bitter foods like bitter melon. His favorite saying is "Even a kappa can drown," and his favorite stone is basalt. Initially, he had no intention of joining the swim club, but he joined after swimming a relay with Rin and the others. His specialty is backstroke, characterized by a smooth underwater dolphin kick. He has won several middle school competitions and earned the nickname "Sea Otter of the Sea of Japan." Although he was not originally a relay member, he was selected just before the prefectural tournament due to his individual backstroke results. Like Nitori, he supported Sosuke, who had injured his shoulder, in participating. His image is that of a sea otter.