Yakumi Hisako

Yakumi Hisako is a member of Academy City Board of Directors who specializes in the medical field. She is the head of the Agitate Halation Project as well as many medical related researches.

Agitate Halation Project Arc
She originally is seen talking to Rensa and she appears to be a "doctor." However, she is actually in a hospital that people do not go to because there are fake rumors that the facility is an anti-terrorism trap disguised as the location of a member of the board of directors. However, it actually is the location of the member in question, Yakumi herself.

Yakumi first tries to jump into an elevator shaft when she sees Tsuchimikado Motoharu who threatens her and  becuase he falsely believes that Kaizumi Tsugutoshi is the person in charge of the Agitate Halation Project. He asks her for information on how to contact Kumokawa Seria and find Kaizumi.

Yakumi has a pink smartphone with the password 7071. She gives the phone to Tsuchikado and allows him to send a message to Seria. In the end, she was manipulating the entire situation the entire time because she is actually the person behind the Agitate Halation project.

Personality
She has  profound influence in the medical field. Her real age is over 70; however, her bones and organs are healthier than Tsuchimikado's because of special anti-aging treatments she has been using.