Shimu (シム, Shimu) is designate leader of the Six Shinshou and the third member to revealed his face.
Shimu has a slight dark hair that have been tied in a thin long ponytail and pupil-less eyes. Shimu displays no emotion, though he sometimes shows slight annoyance with the more hot-headed members of the Shou. So far, Shimu has only been seen in his ceremonial robes.
The most notable characterization about Shimu is that he is emotionless and display lack of concern toward any matter aside from his own personal interest or situation, though there are few times where he does show emotion slightly. Because of losing his human heart and turned into a demon, the only emotion he can feel is hatred toward his own past.
Due to his compose personality and intelligence, he has the most seniority over the Six Shou members and is post as the designated leader which is ironic that he is actually the youngest member in the Twelve Shinshou. However, like all the Six Shou members, he has his limit of keeping his comrades alive. Shimu is cold-hearted toward the lives of people and be willingly to rebel his comrades like Ameeno. Although, Shimu is well mannered and doesn't go far to change plans as being aware of his purpose like how he knew Masato Kadowaki is the only one that can defeat Arata Hinohara and his Tsukuyo.
Shimu's past remains unknown. Though according to Yataka, Shimu became a Shinshou 70 years old which indicates he came from the years when World War II occured.
Shimu appears at the Himou ceremony and Arata's trial, but only in silhouette.
Shimu appears along with the other Six Shou members at the capital in public. The attendants who witness Himuou's age growth consult to inform this news to the minister, but Shimu and Kikutsune order them not to as fearing it will cause chaos and scandal throughout the nation. The attendants reluctantly obey and left. Shimu with the others examines Himuou discussing the matter with Himeou contacting with Hinohara will cause troubles and they create a plan to prevent it from happening.
Shimu and the others decided to have Harunawa switch with somebody who can defeat Hinohara is Kadowaki. After the resonance had been done and Kadowaki transport to Amawakuni, Shimu and the others appear before him much to his confusion and panic. But Shimu manage to calm him down and consult him about his reason for being in Amawakuni.
Shimu leads Kadowaki to Himeou's corpse and persuade him to become a Shou to defeat Hinohara which Kadowaki accepts menacingly much to the Six Shou's delight. They then lead Kadowaki to where Orochi sleeps and Shimu tells him that Orochi requires a Shou who have extreme hatred toward its enemy, Tsukuyo. Kadowaki awaken Orochi and the Six Shou bet on whether Kadowaki will successfully make Orochi his or not.