Karu was the oyabun of the Yakuza and Yuki's father. He also served as one of the main antagonists of Yandere High School. He was also a suspect murderer of Salex though this was proven wrong when Salex's ghost admitted it was Yuki. He was killed by Paul Blart, Sam and Grian in Episode 71 when they shot him to death in a dumpster.
Karu has Brown hair and Black eyes. He has a suit with a red tie and a Black cap. His clump of hair blocks half of his face, including his eye.
Karu was very suspicious when Sam, Taurtis, and Grian met him and his Yakuza members. Karu is a violent,manipulative and evil man who will stop at nothing to achieve his goals even if it means killing people or any one who gets in his way.He is manipulative and sneaky as he constantly tricks Sam into doing his dirty deeds and attempted to make Sam let his guard down so he can kill him. He is also very caring towards Yuki and will do anything to make her happy and even forced Sam to date her.
He loves his daughter and wants the best for her.
Karu is Yuki's father.
Karu affirmed that Taurtis was his son through a letter, even though it was most likely a lie to manipulate Taurtis into not killing him.
Since Taurtis (Jerry), Sam, and Grian (Taurtis) needed a job to get a house, Yuki suggested them working for her dad. At the time they had no clue what they were going to do. When they arrived they started gambling all their money with the other Yakuzas. They lost all of their money when Taurtis went all in. When they were ready to go in Karu's office, he gave them a hit list which had targets they needed to collect money from (JtheStar, PufferFishPete, RowanArtifex, Pepe_Frogman, Mr. Dorito, DaPieLord, and samgladiator). Karu said "As long as you stay with my princess, we have no quarrels with you Sam". They said they would not do it unless, they got cool hats just like them.