Park Kwang-cheol (Korean: 박광철; Hanja: 朴光哲), better known by his Japanese name Kotetsu Boku (朴 光哲, Boku Kotetsu), is a retired Japanese-born South Korean mixed martial artist and kickboxer, competing in the Featherweight division of Rizin Fighting Federation.

Boku made his professional debut against Dutch fighter Marc Duncan at Shooto: GIG East 7 on November 26, 2001, and won by submission in the second round.

He also won his next two fights, against Takuhito Hida and Mitsuo Matsumoto, before losing to Takaharu Murahama at Shooto: Treasure Hunt 6 on May 5, 2002.

They faced each other at GCM: Cage Force 2 on March 17, 2007, and Boku came away the victor after knocking Latomaki out with an elbow in the first round.

It was a loss to Joachim Hansen at the DREAM Lightweight Grand Prix 2008 Opening Round on March 15, 2008.

Boku managed to endure vicious leg kicks throughout the majority of the fight to eventually earn an upset comeback TKO over Moreira early in the third round.

Aoki fought to avenge his Evolve MMA teammate Moreira,[5] and forced Boku to submit at 2:01 during round 2 with a rear-naked choke.