Mitsugu Kakiuchi is a detective assigned to investigate a series of suicides that are linked to a cursed video. His personal motivation stems from tragedy: his wife died as a result of the same curse, and he himself has become cursed. This loss drives him to pursue the case with obsessive determination. He seeks out Detective Yugo Koiso, who had investigated similar events five years earlier, and learns that the suicides are connected to the spirit Sadako and her attempt to be reborn through a human vessel. Kakiuchi's investigation leads him to the young girl Nagi and her mother Akane, who has been in a comatose state while containing Sadako within herself. Convinced that killing both Nagi and Akane is the only way to end the curse, he becomes a threatening force in the story. He attacks and brutally beats Takanori, the father, and later locates Akane in the hospital. When Akane briefly awakens and reaches out to Nagi, Kakiuchi shoots her. Immediately afterward, he commits suicide, having been cursed himself. His character is defined by grief-driven desperation and a willingness to take extreme measures, including murder and self-destruction, in a futile attempt to stop the supernatural affliction.