Tsutomu Sekine (関根 勤, Sekine Tsutomu; born 21 August 1953, in Minato, Tokyo) is a Japanese comedian, singer and television presenter. His former stage name is Rabbit Sekine (ラビット関根, Rabitto Sekine). He is represented with Asai Kikaku. His daughter is tarento Mari Sekine. Sekine is partnered with Kazuki Kosakai, who is a junior at his talent agency and also a longtime best friend, in a comedy duo called Kosakin.
Source: “Tsutomu Sekine”, English Wikipedia (CC BY-SA 4.0), excerpt