Oonuki Yuji stands among seven victims targeted by Fukuda Tamotsu, a serial killer infamously known as the Perforator. While five victims were confirmed deceased, Oonuki and Kazuta Haruka remain officially listed as missing, their survival neither confirmed nor denied. Fukuda inflicted a drilled head wound on Oonuki, though the injury proved non-fatal in the immediate aftermath.

To divert suspicion, Fukuda altered Oonuki’s appearance and attached a drill to his hand, framing him as the Perforator. The ruse succeeded in misleading law enforcement, triggering a confrontation where officers shot Oonuki in the leg to subdue him. His survival and the full extent of his injuries remain unverified.

Available sources lack further details regarding Oonuki’s background, personal history, or appearances in supplementary media such as films, OVAs, or spin-offs.