
Quick answer — Naru Kawamoto voices Takashi Kawamura in The Prince of Tennis, Nugan in Erin, Austin O'Brien in Yu-Gi-Oh! GX and 1 more characters.
Naru Kawamoto voices Takashi Kawamura (The Prince of Tennis), Nugan (Erin), Austin O'Brien (Yu-Gi-Oh! GX), Nozomi Kobuchizawa (Princess Resurrection).
Takashi Kawamura is voiced in Japanese by Naru Kawamoto.