|Occupation||Adult Video Actress|
|BIM Type||Blazing gas|
Yoko Higuchi (樋口 陽子 Higuchi Yōko) is a player in the real-life Btooom! game and a member of Heitaro Togo's alliance.
Yoko is an attractive young woman with long black hair extending down to her shoulders and a small build.
Her attire consists of a red shoulder dress, with a floral-patterned scarf wrapped around the waistline, knee-high heel boots, and a necklace. Like any Btooom! player, she possesses a bandolier and has an IC chip implanted in her left hand.
Although Yoko is motherly toward her allies, she shows little hesitance in assisting the killing of others and justifies such actions through cold logic. She trusts her companions with her life and is willing to aid them. Her interaction with others is usually done in a playful manner, though she also tends to come off as being too familiar. She is also insightful, boasting of her ability to "tell whether a person is lying or not."
Yoko is romantically interested in Heitaro who stops her advances due to his impotence. 
Yoko was known as a famous AV actress under the moniker "Ichiyo." Yoko later claims that her job occupation was made difficult due to the deceitful actions of others.
Accompanied by Heitaro, Kenya Uesugi, and Shigemasa Kusunoki, Yoko pursues Kōsuke Kira, intending to kill him. As the battle progresses, resulting in Kōsuke killing Shigemasa and eventually battling Heitaro, Yoko attempts to find her allies. She later appears and restrains Kōsuke, saving Kenya from being killed by him in the process. Kenya disarms Kōsuke of his BIMs. Shortly after, Heitaro appears, explaining their plan to obtain twenty-eight chips by killing other players in order to leave the island, and invites Kōsuke to join his group, which Kōsuke accepts. Introductions are then made to the Kōsuke, revealing information on each member's past: Yoko's being that she was an AV actress under the moniker "Ichiyo," Kenya's being a "normal employee" and Yoko's "biggest fan," Heitaro's being that he was a former police officer.
On the fifth day, Yoko, along with her companions, ambushed Nobutaka Oda and Hidemi Kinoshita as the two were obtaining a supply case. (With the addition of Kōsuke, Yoko's group has now gained knowledge of how to transfer ownership of one another's BIM within their group and the advantage of the Homing BIM's ability to see the heat signatures of others, which has resulted in the group formulating a more efficient strategy for cornering their opponents.) Although Yoko's group manages to corner the two, the appearance of Ryōta Sakamoto disrupts their strategy, prompting Heitaro to signal the group to come together with the use of sonar waves. As the group assembles, Kōsuke's absence is noted amongst them. Heitaro then sends a sonar wave, revealing Kōsuke moving toward Ryōta. Shortly after Kōsuke's defeat, followed with Heitaro rescuing him, Yoko and Kenya notice Ryōta approaching them. Yoko throws a blazing gas BIM toward Ryōta as she and Kenya attempt to elude Ryōta. Shortly after, they spot Ryōta rushing toward them. Panicking, Kenya throws a Cracker BIM at Ryōta but misses.
After Togo is killed by Shinichiro, in the same time Kira went back to his insanity again, Yoko is killed by a returned insane Kira with a spear while trying to protect Kaguya, whom Togo saved from Shinichiro and survived from Kira's return of his insanity massacre.
Equipment and skills
Yoko seems to know when a person is lying .
- The name Yoko means "light, sun, male" (陽) (yo) and "child" (子) (ko).
- As the AV IDOL, Kazuha, one of her JAV films is featured in Btooom Vol. 16, Kazuha-sensei's Naughty Physical Class. The run time is 240 minutes long. 
- Yoko's surname Higuchi means "gutter, water pipe" (樋) (hi) and "mouth, entrance" (口) (kuchi/guchi).
- Btooom! manga chapter 52 page 42
- Btooom! manga chapter 52 page 28
- Btooom! manga Volume 16, Page 2