Eiichirō Maruo (nicknamed "Ei-chan" for his grades being straight "A") is an honor student, bookworm, and is not interested in anything other than studying. In order to solve his problem of lacking physical strength, he enrolled a tennis school and soon found the fascinating side of tennis. Being a tennis newbie lacking physical strength, he supplement his shortcomings with his excellent observing and analyzing skills.

• Taishi Murata
• Minako Kotobuki
• Daisuke Namikawa
• Asami Seto
• Hiro Shimono
• Taiten Kusunoki
• Takuma Terashima
• Tetsuya Kakihara