At the same time, he joined the amateur division of mixed martial arts promotion Shooto, training under Satoru Sayama at the Super Tiger Gym.

In 1994, Nakai took part in the Vale Tudo Access series of events and fought Brazilian Jiu-Jitsu exponent and Rickson Gracie student Arthur Cathiard in the first of them, getting a draw after an uneventful bout spent at Yuki's guard.

At the second, the Japanese dropped down and initiated a heel hook entry, only for Gordeau to clamp himself to the ropes again and land strikes on his supine opponent, eye-gouging him illegally several times.

Finally, after a third round passed on the ropes, Nakai scored a double leg takedown against the ring corner, escaped from a guillotine choke attempt by Gordeau and dropped down for another heel hook, this time managing to submit the Dutchman after half an hour of fighting.

Despite his right eye being gravely injured and having lost half of his eyesight,[4] Nakai advanced round in the tournament and went to the ring to fight against American Wrestler Craig Pittman, who sported a full 100-lb weight advantage.

The Brazilian advanced to a cradle position and followed by taking full mount, from where he landed some punches before catching Yuki in a rear naked choke for the tap out, thus winning the tournament.

After retiring from MMA, Nakai became interested in Brazilian Jiu-Jitsu, not due to his own defeat to Rickson as it is popularly believed, but to Noboru Asahi's loss to Royler Gracie in 1996.