Johnny Mo was the leader of the Crazy 88, serving under the leadership of O-Ren Ishii.
Working With O-Ren Ishii
After the Massacre at the Two Pines chapel, O-Ren took control of major Japanese corporations; causing her to control some of the Japanese Yakuza, including the Crazy 88. Since she controls the Crazy 88, Mo must follow her orders and he and his group become her main army of Yakuza fighters.
Showdown at the House of Blue Leaves and presumed Death
After Beatrix Kiddo woke from her four-year long coma, she hungered for revenge on the Deadly Viper Assassination Squad and wanted to kill all of the members within the Squad. Beatrix traveled to Tokyo, Japan, to kill O-Ren Ishii first. While Beatrix was fighting against some of O-Ren's guards and Gogo Yubari at the House of Blue Leaves, O-Ren secretly tipped off the Crazy 88 to arrive and kill Beatrix. Mo battled alongside the Crazy 88 to try to kill Beatrix. He fought the Bride one-on-one three times. He is a more proficient fighter than the rest of the gang, nearly tipping the scales in their favor and holding his own against the Bride for several minutes alone while fighting her on top of a balcony railing. However, Beatrix eventually chops off both of his legs, and he falls into a pond from that second floor balcony and is presumed dead thereafter.
- His weapon of choice is a pair of shōtō.
- Michael Madsen was Quentin Tarantino's original choice to play Mo.
- According to the script, the character was a huge fan of "hammer and sexploitation" films of the 1970's.