Kamui Katsuragi is one of the main characters in the Cardfight!! Vanguard anime, manga, and Cardfight!! Vanguard G. In the beginning of G, he serves as a mentor to Chrono Shindou, much like Shin Nitta was to Team Q4, and is responsible for the creation of Team TRY3. His vanguard circle is orange. (Source: Cardfight!! Vanguard Wiki)