
Quick answer — Mayumi Yamaguchi voices Gabumon in Digimon: Digital Monsters, Jianliang Lee in Digimon Tamers, Forte Stollen in Galaxy Angel and 10 more characters.
Mayumi Yamaguchi voices Gabumon (Digimon: Digital Monsters), Jianliang Lee (Digimon Tamers), Forte Stollen (Galaxy Angel), Masaru Katou (Gantz: Second Stage), Sousuke Kawara (Samurai Champloo), Envy (Fullmetal Alchemist), Leise (Ascendance of a Bookworm), Gachagiri (Den-noh Coil) and 5 more.
Gabumon is voiced in Japanese by Mayumi Yamaguchi.