Information:
These two seiyuu (voice actors) both voice characters in the popular anime One Piece (Usopp and Chopper respectively). Each of them also have other noteable roles:

Yamaguchi - Saotome Ranma (Ranma 1/2), Tonbo (Kiki's Delivery Service), Inu Yasha (Inu Yasha), L (Death Note).

Outani - Pikachu (Pokemon), Hasegawa Sora (Ah! My Goddess), Tsuburaya Mitsuhiko (Detective Conan series), Shiratori Yukina (Martion Successor Nadesico), Gash (konjiki no Gash Bell).