|Kanji Name||柴崎 芦花|
|Height and Weight||143 cm, 33 kg|
|School||Fujou High School|
|Class and Year||2-A|
|Club||Game Creation Club (Provisional)|
|Relatives||Tsutsuji Shibasaki (Little Sister)|
Shibasaki Roka is a second year student at Fujou High School and the President of Game Creation Club (Provisional), she refers to her element as Fire. However, her true element is Darkness which is how she got the epithet of Ultimate Darkness (最高 の 闇 , Saikō no Yami) who is known as someone who can defeat enemies easily with her bag attacks.
She is also known as The Rear Boss (裏 ボス, Ura Bossu) of Fujou High School who is rumored to be the strongest person in school.
Roka is a petite girl, having brown eyes and short blonde hair which she ties into two pigtails on either side of her hair. She is most commonly seen wearing her School Uniform, which has the stockings covering up her legs entirely.
Roka's strange personalities and habits tend to make others think she's weird. However, she is very optimistic, but she has hinted at some points that she was a yandere. She also never gives up when she has a goal in mind, like when invited Kenji to join her club, called Kenji as a member who has been eagerly awaited while saving him from falling out a window. Sometimes, she suddenly exhibits a spoiled personality when becaming moe, which fails to affect people like Kenji, but she also has a darker side that can intimidate just about anyone. She is also rather gullible to some extent, as showcased by her either not noticing or caring about Kenji's "cosplay" having a much larger back than usual (it was in fact Takao trying to hide.).
- During her childhood, Roka met Chitose presumably in a sandbox. Roka learned that Chitose was always being bullied by Tama, so she then taught Chitose to be brave and to get her hands dirty in order to achieve her goals. Since then, she became Chitose's close friend, and has been aware of the rivalry Chitose and Tama had up until her second year in high school.
- When entering highschool, she then joined the Game Creation Club of Fujou High School, and became friends with Takao. However, due to her strange behavior, the other members ostracized her, which prompts Chitose to bury the members up to their necks in the ground so she could avenge Rok. After that event, the members of the game club had slowly begun to leave, including Roka, who felt guilty after what happened, leaving Takao's group on the brink of destruction.
- After she left Game Creation Club, Chitose tried to help her best friend by helping her form a new game development club. After some time, they formed the Game Creation Club (Provisional).
- When she was in her 1st year, she made a bag and met Hachi Shiou, whom had a crush on Roka. Hachi tried to get her bag, but Roka retaliated by shoving her bag over his head. Since then, Shiou claimed that Roka has captured his heart, and has been trying to win her affections ever since.
- When she was in her 2nd year, Roka's friend Takao became the President of the Game Creation Club.Takao planned to ask Roka to rejoin her club so they could be friends again, but Roka had already made a new club. Takao has since that point held a grudge against Roka and has been trying to disband her club.