Dragon Drive Vol 1

Dragon Drive Vol 1 by Ken-Ichi Sakura. A Shonen manga rated All Ages, published in English by Viz Media in 2004.

Reiji is a kid who gives up on everything, until he discovers Dragon Drive, a virtual reality game where players battle with dragon partners. His dragon is a tiny, sleepy little guy named Chibi, but there's more to him than meets the eye. A fun monster-battling adventure.