Kazuki (カズキ Kazuki) is a young blader and Yui's older brother.
Kazuki and his sister Yui appear in the episode, Rock Scorpio's Deadly Poison where he launches his bey at Kenta but is easily beaten. He later reveals that the bey-park in the area is being manipulated by Busujima and his gang. He then helps Sora get stronger in order to beat Busujima. In a battle against Busujima, he is defeated and his bey is smashed into pieces. He later helps Kenta free his sister, Yui.
Yui is Kazuki's little sister.
- Wind Leone 125WB is destroyed when Busujima stepped on it.