Like all members of the Public Morals Committee, Yobuko is dedicated to upholding school rules, and will not hesitate to use violence if she deems it necessary. Though she usually appears quite cordial, Yobuko reveals a rather psychotic side when dealing with troublemakers on Myouri Unzen's orders. As Unzen's partner and second-in-command, she appears to be in a much more intimate relationship with him than mere fellow workers. Yobuko lets him sit in her lap, feeds him, lets him nestle his head in her breasts for comfort, and seems to even wear a naked apron for him.
Yobuko has waist-length, light brown hair (though colored blonde on one occasion), and light purple eyes (originally colored brown in the manga, and brown also in the anime). She wears the uniform of the Public Morals Committee with a red ribbon around the collar, as well as a pair of glasses. She is first seen wearing red shoes and stockings, though she later forgoes the stockings and instead wears white shoes. Her shoes are black in the anime. When dressed casually, Yobuko wears a light colored sweater over a collared shirt, with both sets of sleeves rolled up. She also carries a handbag over her right shoulder, and wears a skirt. Ten years later, Yobuko wears an outfit similar to her Enforcer uniform, and a hat.
Student Council Executive Arc
Yobuko is seen standing with Unzen, Harigane Onigase, Kanraku Kunisaki, and Rankaku Yoshinogari behind the other students at Medaka Kurokami's inauguration ceremony. In the Public Morals Committee's office, Yobuko reports to her superior about Onigase's two successive failures. Though she suggests they punish her, Unzen tells her to let it go, and asks after Medaka. Yoboku goes on to describe Medaka as a saint, and notes that her suggestion box is extremely popular. Yobuko orders Onigase to take a towel to Unzen at the music room, hoping it will improve the younger girl's work ethic. She goes on to describe what Unzen is like. Not long after, she sneaks up behind Zenkichi Hitoyoshi as he is working, with her weapon drawn. Yobuko calls a large group of Enforcers together to stop Medaka while she handles Zenkichi. Yobuko makes herself known to Zenkichi, asking him to carry some boxes for her, and comments that he seems used to hard work. When Zenkichi answers that he has heard the same about her, she acts embarrassed, before agreeing and revealing that she has attacked multiple people on Unzen's orders. She then attacks Zenkichi from behind with several chains hidden in her sleeves, only to be stopped by Medaka. Stunned by the other girl's entrance, Yobuko can only think to herself that Medaka is not normal.
Yobuko contacts Unzen to report the mission's failure, after confirming that both Yoshinogari and Kunisaki were intercepted by Medaka as well. She goes on to tell Unzen what Zenkichi had told her, but dismisses it as a bluff, stating that the really amazing thing is that Medaka was able to resolve the conflict with no one from either party getting hurt. Yobuko then hears a sharp noise from the phone as she is cut off, and wonders what happened. After Medaka finishes her fight with Unzen, Yobuko arrives at the Student Council office with Onigase, both concerned for their leader. Yobuko tries to clean up his face with a handkerchief, and immediately obeys when he tells her she will have to work harder now that he is out of commission.
Thirteen Party Arc
In the lunch room, Yobuko sits with Unzen in her lap as the boy explains the Flask Plan to several Enforcer girls. Unzen identifies Yobuko and the girls as Specials, then goes on to explain Abnormals and the dice test. When Unzen expresses his desire to talk with Zenkichi, Yobuko is somewhat surprised. As Unzen describes his sister, Myouga Unzen, Yobuko feeds him some cake. Yobuko listens along with the other Enforcers as Unzen describes his sister.
Kumagawa Incident Arc
At the end of the semester, Yobuko is present for Medaka's speech. She is surprised by Misogi Kumagawa's sudden entrance, and declaration that he is Medaka's ex. On August twenty-second, Yobuko is among Medaka's former enemies who show up to cheer for her during the President's Battle.
Kurokami Medaka's Successor Arc
Unknown Shiranui Arc
Bouquet Toss To The Future Arc
Weapons Specialist: As an Enforcer, Yobuko is allowed to carry weapons while in school. Her weapons of choice are several chain whips with spikes affixed to the ends, which she keeps concealed in her sleeves.