Momotarō Mikoshiba is a supporting character in Free! The Movie -Timeless Medley- the Bond. He is a first-year student at Samezuka Academy and the younger brother of Seijūrō Mikoshiba and Isuzu Mikoshiba. He has short orange hair and yellow eyes, stands 172 centimeters tall, and was born on December 6, making him a Sagittarius. Momotarō is known for his bright, loud, and highly energetic personality. He is an upbeat and self-assured young man who tends to act before thinking, and he shares his older brother’s tendency to fall in love easily, frequently attempting to impress Gō Matsuoka—though she can never quite remember his name. His primary motivation in the story is to compete seriously as a swimmer and to prove his abilities to his teammates and rivals alike. He holds a deep admiration for Rin Matsuoka and looks up to him as a leader and a standard of excellence within the Samezuka team. In the Timeless Medley films, his role is that of a supporting teammate who contributes to the relay team and helps maintain the spirited atmosphere of the Samezuka swim club. His key relationships include his brother Seijūrō, who acts as both a sibling and an informal mentor, and his fellow Samezuka swimmers Rin Matsuoka, Aiichirō Nitori, and Sōsuke Yamazaki. Over the course of his appearances, Momotarō develops from a boastful newcomer into a more reliable and cooperative member of the team, learning the value of teamwork and perseverance alongside his personal ambition. His notable ability is his specialization in backstroke, in which he displays strong speed and a distinctive underwater dolphin kick known as a bodysurfing technique or basaro. His hobby is collecting stag beetles.