 In 1999, Numata had a one-off ride on the Muz 500 as a replacement rider for Luca Cadalora in the 500cc class, finishing 13th in the race.He also made one-off appearances in Supersport World Championship and Superbike World Championship races in and , but retired on each occasion.Numata, like many of the top Japanese riders, was also a regular competitor in the Suzuka 8 Hours Endurance race.