Tatsuya Rukawa

Nicknamed "Tiger Killer Ryu", Tatsuya is the third "father" of Motoko to be revealed. He is mainly a wanderer and is described the karate master that "defeated a tiger with his bare hands". He is also responsible for the creation of Hibiki. He is a specialist in empty-handed combat and known throughout the underworld as an 'untouchable' having taken vengeance on a number of gangs, mob bosses and professional fighters for slighting him. Like Hibiki, if there's a fight to be had he's always anxious to join in and has even been known to instigate fights, despite any odds. He refers to Motoko and HiFuMi as his daughters, and Kosukegawa as his son-in-law. Of the "three fathers", he is the least involved in Motoko's life, though he's her registered guardian. (Source: Wikipedia)