Wataru is a skilled driver who honed his skills on the treacherous Shomaru Pass. He came to Gunma in hopes of facing new racers to challenge, as well as to watch over his sister Kazumi, who just got a job at a hotel with her aunt. He was first seen appearing at Akagi to spectate the battle between Ryosuke Takahashi and Kyoichi Sudo.
Later on, after finding out from Keisuke Takahashi that Ryosuke was defeated by another lone racer from Akina who also used an AE86, which was Takumi Fujiwara, Wataru decided to battle against him instead. Earlier he wanted to battle Keisuke at Akagi, but Keisuke declined since it was against the RedSuns' policy to race in their home turf. Still not satisfied, Wataru engages in an impromptu battle, with Kenta spectating behind them. Keisuke and Kenta soon realizes this was no ordinary Eight-Six, as they noticed from its speed and the engine sound, from which they understood it was turbocharged. The battle ended as they both skid to a halt from a crashed car in the middle of the road. Wataru vows to battle with Keisuke later on, with Keisuke looking for the same.