Yakou is a tall and muscular man with rather pale skin and dark blue eyes, with irises designed to look like two squares with one inside the other. His hair is short and wavy, only reaching just below the ears, and is dark blue, like his eyes. Yakou is an aloof and elusive man who is described to be intelligent despite not having a forte of his own. Now revived thanks to homunculi immortality, he became a lot more reserved and silent, but still kept his old personality.