Yoji Shono (1983-January 2019) was a Japanese scientist who, while serving as the lead researcher at the Advanced Drug Development Center (ADDC), developed the AD-9 drug to cure Alzheimer's. After Shono accidentally killed the patient Koichi Waku during a secret test of AD-9, he was forced to carry out a series of murders both to cover up AD-9's defects and to continue testing it on unsavory types such as the ADDC's enemies from the Kyorei-kai yakuza. The AD-9 conspiracy was unraveled by private detective Takayuki Yagami in 2018, and Shono, still confident in his invention, accidentally killed himself by injecting himself with what he believed to be a successful, final form of AD-9.
Biography[]
Yoji Shono was born in Tokyo, Japan in 1983. His grandparents suffered from Alzheimer's disease, and, after they died, his mother - who had served as their caretaker - collapsed and died as well. This experience left Shono with an intense passion for curing Alzheimer's, believing himself to be God's servant. He became a scientist and came to be the ADDC's head researcher, in which capacity he developed the AD-9 drug to cure Alzheimer's. After the animal trials on mice were successful, Shono secretly initiated clinical trials, testing it on the Alzheimer's patient Koichi Waku in 2015. However, Waku was killed by the injection, forcing Shono to dump the body in a laundry basket placed in the janitor Shinpei Okubo's truck. Okubo accidentally implicated himself when, in a panic, he chose to bury the body in the mountains rather than report it to the police, with whom he already had a record. While Okubo was arrested, he was proven innocent by the lawyer Takayuki Yagami.
Shortly after, ADDC director Ryusuke Kido announced AD-9 at a press conference, with a nervous Shono in attendance. Shono admitted to Kido that the drug was completely lethal to humans and that he had killed Waku, but he assured Kido he could fix the drug. Kido, aware that the development of AD-9 was ADDC's only hope of staying alive in the wake of Toru Hashiki's sabotage, agreed to help cover up Shono's murders. To frame the acquitted Okubo for Waku's death, Shono visited his Tokyo apartment and injected him with alcohol before stabbing his girlfriend Emi Terasawa fifteen times and burning down their apartment. Okubo was widely believed to have drunkenly murdered his girlfriend on leaving jail, and he was sentenced to death.
This conviction gave Shono the time to focus on covering up AD-9's failure, enlisting the help of the bent cop Mitsuru Kuroiwa (through his allies, Vice Minister for Health Kaoru Ichinose and Matsugane-gumi captain Kyohei Hamura) to bring him live test subjects from the rival Kyorei-kai (who backed Hashiki's saboage of the ADDC in a bid to close it down and redevelop its land). Shono tested AD-9 on Kenkichi Mashiba, Yasuo Kunimura, and Toshiro Kume from August to December 2018, using a secret lab at the closed-down Monsieur Lee love hotel as his base. When the men died and their eyes assumed a blue pigmentation, Shono covered up AD-9's failure by having Kuroiwa remove their eyes, causing him to be nicknamed "the Mole."
In December 2018, Yagami - now a private detective after being disgraced by Okubo's acquittal and subsequent murder of Terasawa - was hired to help defend Hamura in court after Hamura was charged with Kume's murder. After Yagami secured Hamura's acquittal, however, he became curious about the true murderer, whom Hamura seemed to know. This investigation caused him to be threatened by the Matsugane-gumi, the Kyorei-kai, and even the ADDC itself, and he ultimately headed to the ADDC to confront Kido and, later, Shono after they had the lawyer Masamichi Shintani murdered for catching onto Shono's involvement in the murders. Yagami and Issei Hoshino chased a frightened Shono down to Koichi Waku's old room and interrogated him, but he feigned ignorance until Kido could arrive and force the two men to leave. Shono was later confronted by Yagami at his Monsieur Lee secret lab after Yagami tailed Mitsuru Ishimatsu there, but chief prosecutor Kunihiko Morita - who was in league with the AD-9 project - forced Yagami to leave and did not authorize the police to investigate the lab.
During Kazuya Ayabe's trial in January 2019, Kuroiwa confronted Shono at the ADDC, determined to kill him and cover up his tracks. When the police arrived to confront Kuroiwa, Shono fled, only to be shot in the shoulder by Kuroiwa. Yagami and Fumiya Sugiura moved Shono down to a nearby lab room to prevent him from being killed. Kuroiwa later attempted to charge Shono with a knife, only to be shot by nearby police. Shono gloated to a dying Kuroiwa that AD-9 was complete, and, to celebrate his perceived success, he injected himself with a syringe of AD-9, only to suffer from an extreme headache, blue pigmentation of the eyes, and then death.