Kenji is a manga about a Japanese teenager named Kenji, who practices the martial art Bajiquan, and his encounters with other martial artists, some of whom are from real life (e.g. Adam Hsu and Liu Chia-Liang). This series primarily features Bajiquan, but also gets into Tanglangquan, Baguazhang, Chen Taijiquan, Piguaquan, Xingyiquan, Xinyiliuhequan, Shaolinquan, Hung Gar, Daito ryu Aikijujutsu, Shotokan Karate and numerous other styles. Kenji's archnemesis is a gangster named Tony Tan who practices Hung Gar and later Xinyiliuhequan.

The series is based on the life of the author, Ryuchi Matsuda (Song Tian Long Zi in Mandarin), who has history involving Hakkyoku-ken (Bajiquan), Li Shu-Wen, and Liu Yun Qiao.