Kazumi Onimaru is the main antagonist in Cardfight!! Vanguard G: NEXT, and later a secondary protagonist in Cardfight!! Vanguard G: Z. He was forcefully Diffriden by Stealth Dragon, Shiranui up until the final episode of NEXT. Kazumi feels remorse and feels that he was too weak to help out Shiranui. Kazumi's true personality is shown to be similar to the persona used by Shiranui when he first encountered Chrono. He use's Nubatama Deck and "Stealth Dragon, Shiranui" as his ace.