Shuichi Aizawa operates as a member of the Japanese National Police Agency and the Kira Investigation Task Force, demonstrating unwavering commitment to lawful procedures and expressing consistent frustration toward unconventional investigative methods. This dedication sparks conflict when Task Force funding ceases. After learning the financial withdrawal was a deliberate test, he resigns to prioritize family obligations but later rejoins to aid in capturing the third Kira, Kyosuke Higuchi. Following L's death and Light Yagami's assumption of the L identity, Aizawa continues on the Task Force under Light's command. He becomes the first member to suspect Light as Kira, initially suppressing doubts out of respect for Light's father, Soichiro Yagami. Near, L's successor, later contacts the Task Force, voicing suspicions about Light while referencing information allegedly inherited from L. This steadily erodes Aizawa's hesitation to investigate Light. Aizawa escalates his probe by discreetly marking notepads used during Light's meetings with Kiyomi Takada. The disappearance of these marked notepads after meetings confirms clandestine communication, cementing his belief in Light's guilt. He shares this evidence with Near, who directs him to sustain surveillance without independent action. Aizawa witnesses Near expose Light as Kira at the Yellow Box Warehouse and observes Light's subsequent death. After Kira's defeat and Near's rise as the third L, Aizawa ascends within the NPA, succeeding Soichiro Yagami as deputy director. In "Relight 2: L's Successors," Light assumes the L role four years after the original L's death. The OVA features Teru Mikami killing dissenters through unnatural methods, such as twisting a victim's head 180 degrees. Near accesses L's original case files, framing his interactions with Aizawa and grounding his accusations against Light from the Task Force's perspective. Aizawa's trajectory emphasizes his lawful integrity, mounting suspicion of Light, and critical role in enabling Near's investigation.