Self-proclaimed 100-Dan Karate Master.
Sakaki's scarred face, short temper, imposing physique and boorish manner mark him as a fairly macho, unapproachable figure, an image further complimented by his love of gambling and drinking, but underneath it all he's ridiculously soft. Despite repeated, loud declarations that he never takes on students, Sakaki is one of the masters most attached to Kenichi, and can become anxious or surly whenever Kenichi is absent or in danger.
Sakaki has no fixed income, but instead makes his money through gambling or infrequent but high-paying bodyguard jobs. Alike Akisame and Ma Kensei, he doesn't just teach martials arts knowledge to Kenichi, but offers personal guidance as well.
As one of the masters at Ryozanpaku, Sakaki can be regarded as one of the most powerful martial artists in the world. As such, he frequently performs feats impossible for ordinary human beings, such as shattering concrete walls, surviving falling from a fatal height, knocking opponents further than humanly possible etc. He is a martial artist of the "Dou" type, meaning that he is someone who uses anger to exceed his usual physical limits.