Taishi Miwa

Taishi Miwa is a supporting character in Cardfight!! Vanguard. He is a friend of Toshiki Kai; they have been friends since they were young, and he's Kai's closest friend. He understands Kai and plays Vanguard with him. Unlike Kai, Miwa is friendly towards people and loves to joke around. He also attends Hitsue High School with Kai.

(Source: Cardfight!! Vanguard Wiki)