Yoshiaki Ide is a tennis player from the Saitama Prefecture. He first appears in the All-Japan Junior Indoor Selectionals, Kantou Preliminaries where he defeats Hiroto Narikiyo and is described as a player with high mental strength by Yu Nabae. As a tennis player, he is very good at reading the instinctive rhythm and tactics of an opponent's play, and responds quickly. In addition, he attracts the audience with his aggressive plays. He is seen to be always smiling and laughing. (Source: Baby Steps Wikia)
Hiromi Iwasa studies at Sekei High School. He was the fourth seed at the first Kanagawa Junior Tennis Circuit and the third seed at the second competition. He decides to quit tennis after losing to Eiichirou Maruo and graduating from High School. (Source: Baby Steps Wikia)
Mogami Norihiko is a tennis player in Kanagawa and attends the same school as Takuya Miyagawa and Ryou Oobayashi. He is first introduced in a match against Eiichirou Maruo in the third Kanagawa Junior Tennis Circuit where he was the 2th seed.
Hiroto Narikiyo is a regular tennis player at the Kantou Tournament. He has a lot of fans due to he good looks. He is first seen playing against Yoshiaki Ide who defeats him in 2 sets. (Source: Baby Steps Wiki)
Atsushi Taira is a Japanese tennis player who plays at the Florida Tennis Academy. He is acts as the translation for Eiichirou Maruo, and claims to be famous in Japan. He is a professional tennis player training together with Krishna and Alex.