After a 10–0–4 career in Shooto, Kawaguchi represented the promotion in the event Vale Tudo Japan in July 1994, where he was pitted against French karateka Jan Lomulder.
A controversial moment happened when Kawaguchi tried to return to the ring, as the referee didn't stop the action, meaning Lomulder could freely score soccer kicks and stomps while he did so.
The Shooto wrestler repeated the takedown, but Lomulder grabbed the ropes again and landed multiple elbow strikes to the back of the head, and then followed with and more soccer kicks and stomps.
After a restart, Kawaguchi tried to come back with a kneebar, but Lomulder blocked the technique and landed a heavy kick on the face, leading the referee to stop the match.
This time, the match lasted three rounds, and it saw the Japanese shoot wrestler eventually taking Lomulder down and executing a rear naked choke for the victory.