|Anime debut||Episode 8|
He looks like an older middle aged man wearing a green shirt with a black jacket and brown pants. He wears a watch and wears nice brown shoes his wife bought. He has wrinkles, showing signs of old age just starting to come on and grey eyes with his brown hair combed back.
Initially, he was shown as dedicated to his job to the point he forgot his own birthday. He was rational in a situation and his years as a detective allowed him to tell if a person was a liar or not and read their motions and actions to determine what kind of person they were. He was also shown to be friendly and open to those who he considers friends, or at least good acquaintances, as he told Shimada to call him by his name rather than the more formal detective title and the two worked together during the game to try to find a way out. These seem to be remnants of his former personality until the death of his wife which turned him into a pathological killer as he sought revenge and murdered her killer, only to hear her voice thanking him, beginning his long delusional self righteous quest of using his job as a detective to witness the actions of those he considered "scum" and judge them based on how they hurt or assaulted their victim. He showed no mercy in his goals, allowing multiple innocent people to get hurt in order to judge those who hurt them and killed them. He believed there were people who truly deserved to die and even corrupted Shimada into becoming a mirror image of him by egging him about how weak he was and how he didn't help his sister from being raped as there had to be a victim to judge the rapist's actions. He was uncompromising, cold, heartless, and immoral, becoming a murderous self righteous man who sacrificed morals and people for his own goals, regardless of how they were affected. He kept a cool head as he accepted the death but disliked how Shimada stabbed him with the same knife that had the blood of the rapist, showing he is a hypocrite. He will also lose his composure when people criticize his conviction and "Judgements". He even likes the idea of arbiter and considers himself one as in both cases, they are people who draw the darkness out of other people and wait for a victim to occur and judge people who are "below them".
Tatsumi was once a proud, esteemed detective who worked long days and nights. He would even forget his own birthday but his wife was patient and loving towards him, understanding the importance of his job and supporting him. However, one day after coming home he found his wife brutally murdered. He immediately sought and murdered her killer. In his delusional state he "heard" her voice thank him, beginning his long self righteous quest to murder "criminals". He would tail them, allowing them to victimize someone and then brutally murder them. Eventually, however, after a rapist assaulted Shimada's sister Sae, Shimada sought revenge against her rapist and Tatsumi, his supposed accomplice. He eventually succeeded and when Tatsumi came into the stalker's apartment to kill the rapist as well, Shimada killed Tatsumi and then died from the stab wound the rapist gave him.
- He compares himself to an arbiter, drawing a dark parallel between the two as both believe themselves better than those they judge and allow them the chance of life and death depending on the darkness of their hearts.
- He was a habitual smoker.
- The shoes he wore were given to him by his wife.