Fists of Fury: Clash of the Gentle Fist and Strong Fist

Forty-fourth Training Ground
''While preparations go on for Konoha to host the next Chūnin Exams, the commander of the Konoha Military Police Force goes on an last minute security check of the Forest of Death. While there he encounters a young man practicing taijutsu.''

Sōsuke walked into the clearing to see a young man training. Seeing him practice there when the training ground was off limits just ticked Sōsuke off. He picked up a pebble from the ground and threw it at the young man. "Kid," he shouted. "You know you are not supposed to be here right now. Better clear out, unless you want to get into trouble."