Akira (アキラ) is a mysterious and eerie boy who seems to possess an uncanny resemblance to Teru Kurebayashi's older brother, Soichiro. However, as a number of characters note upon seeing Akira clearly, he does not actually resemble Soichiro that closely. He often has a wide grin that makes him appear maniacal and he usually carries a yo-yo around. To conceal his appearance, he wears a hoodie.
Akira's behavior is erratic and seemingly remorseless, though he is exceptionally attached and affectionate towards Chiharu Mori, whom he works with as an accomplice. His motives for causing trouble for DAISY are unknown, though he appears to garner a great deal of enjoyment from upsetting Teru Kurebayashi and Tasuku Kurosaki. He also blames Kurosaki and wants revenge on him for undisclosed reasons, often using his vindictive interest in Teru to hurt Kurosaki.
Little is known about Akira's background, though he is later identified as a gifted hacker from the cyber mafia, Hyperion. However, he is a very poor operative due to his childish emotional state resulting from the special treatment he received until that point. He has also been hospitalized for an unknown illness. His apparent goal appears to be related to Professor Hideo Midorikawa's last testament and taking revenge against DAISY.
Early in the manga, Akira is seen periodically and seems to be behind the imposter DAISY incident. After Tetsuya Arai is captured and Chiharu Mori is exposed as the culprit, Akira appears before Teru, who notes his passing resemblance to her deceased brother. Akira steals Teru's wallet and approaches her when she is searching for it; he frightens her off by stealing her first kiss. He later appears at the grave of Hideo Midorikawa when Riko Onizuka goes to visit the cemetery.
In Akira's subsequent appearances, he is revealed to be associated with Chiharu Mori and intent on taking revenge on DAISY while hurting Teru to maximize Kurosaki's agony. He confines Teru to a car on a ferris wheel and tricks her into sending a message to Kurosaki that states she cannot forgive him for causing her brother's death. Teru learns from the encounter not to fall for Akira's traps and rejects him when he offers a way for her to reunite with Kurosaki after he disappears.
When Rena Ichinose is engaged to Kazuki Morizono, Akira manages to assault Teru in a hotel elevator. She is saved by Kurosaki, who threatens and knocks Akira unconscious. Chiharu arrives to take Akira away and Akira is later seen in a hospital bed. When Teru and her friends go to rescue Rena and stop Morizono from auctioning off a new version of Jack Frost on a cruise ship, Kurosaki finds Akira unconscious in a storage room and in need of medical treatment. After making a remark about Professor Midorikawa's last testament, he provides Kurosaki with the necessary password to open the door to Morizono's room and save Teru. In exchange, Kurosaki deposits Akira outside the door where Chiharu Mori will recover him.
After the Neo-Jack Frost incident, its perpetrator Kuwagata reveals he had promised Akira that the latter would be rewarded with the key to "M's Last Testament" if he followed orders. Furthermore, Kuwagata adds that Akira was not a blood relation of Midorikawa's and that the professor had likely forgotten him. Akira is sedated by Chiharu when he tries to attack Kuwagata, who comments that he has retained Akira's services because he is "still entertaining." When Chiharu returns to check on Akira's condition, she discovers that he has gone missing.