Vyga, known as Kōji Dōmoto in the Japanese version, is a character appearing in the Tag Force series. He is a Ra Yellow student.
In Yu-Gi-Oh! GX Tag Force, Vyga can often be found at the Obelisk Blue girls' dorm. He has a particularily formal manner of speech in the Japanese version, which the Western releases downplayed slightly to make him sound more easily excitable.
The player is able to give Vyga sandwiches. The following tables detail how much he likes or dislikes the sandwiches.