OVA
Description
Toru Souma emerged from a childhood as an orphan subjected to brain enhancement experiments, granting him unique resistance to mental modifications like brainwashing or forced amnesia. Originally Shinichi Mizusaka, adoption into Tsukina Sasagiri's family made him Ren Mizusaka's step-brother and forged a close, complex bond with Tsukina. After his adoptive father's death, Toru turned to hacking for survival, founding the gray-hat group Steppen Wolf with friends Yuuya Nonomura, Tsukina, and Akira Nikaidou. They began stealing data for profit, later pursuing high-profile targets for recognition.

Steppen Wolf's dissolution started when Yuuya planned to disband for a lawful life. Their final hack targeted a military server operated by FLAK – a trap for terrorists. Caught in a crossfire between FLAK and Fei Dao terrorists, Yuuya was killed by an unidentified FLAK Simulacrum pilot (later revealed as Ayane Shidou, acting unintentionally). Toru witnessed Yuuya's death and a mysterious blue-haired girl. Arrests followed, with Akira imprisoned for accessing classified data. To avoid incarceration and avenge Yuuya, Toru joined FLAK as a Simulacrum pilot.

Within FLAK, Toru's path diverged. His core motivation remained uncovering Yuuya's killer, symbolized by retaining Yuuya's mini-knife – a weapon in cyberspace. This quest often drove him toward revenge, though allies like Minori Segawa or Ayane could shift his focus toward justice or protection. In some routes, learning of FLAK's corruption, especially involving the VSS division and leader Reika Tachibana, led him to desert and join Fei Dao. Reika exploited his grief, promising vengeance for Yuuya and attempting to brainwash him into subservience, but his experimental mental resilience resisted. His relationship with Tsukina evolved from supportive stepsiblings to romance, complicated when Reika manipulated Tsukina into destructive cybernetic enhancements.

Toru's forgotten past gradually resurfaced. Fragmented memories revealed his childhood in an isolated forest home with Qu Wong, Liang, Genha, and Bachelor – all later test subjects for brainchip experiments. The enigmatic blue-haired girl he saw was Ren Mizusaka, his biological sister, existing as a digital ghost due to experiments linking her consciousness to the network. Ren's appearances guided Toru toward revelations about their shared history, the brain enhancement program, and Reika's role, culminating in him reclaiming his identity as Shinichi and confronting Reika to resolve Ren's fragmented existence.

Balancing technical prowess as a hacker and Simulacrum pilot with emotional vulnerability from loss and identity struggles, Toru's development varied. Outcomes included achieving closure by exposing institutional corruption, succumbing to despair as a mercenary after killing Ayane, or sacrificing autonomy to protect Tsukina. A recurring theme was his navigation between virtual and real worlds, questioning reality while confronting forces manipulating both realms.