Despite his role as a villain, Kaku is surprisingly honest, even to his enemies and even more so than Fukurou, though he does not seem to take insults well. He also talks like an old man, as remarked by several characters, despite being only 23 years old. He uses the term "washi" From his training as a Rokushiki master, Kaku has worked hard to develop his immense physical power since childhood and could match the formidable Roronoa Zoro in terms of strength. He has tremendous speed and agility.