(from ebookjapan):

Bui Hazama, 15 years old, also known as Victory Hazama, or V Hazama, is a man who, as his name suggests, has never lost a fight in his life! After the death of his foster parent, Gen-san, V is traveling alone in search of his parents, who separated when he was a child.

During his journey, V by chance tries tennis for the first time in his life, and beats a tennis player ranked 5th in Japan by playing tennis beyond the norm. The challenge of a man who was born and raised to win, while carrying a secret past!