Call of Duty is the 30th chapter Ajin: Demi-Human, created by Gamon Sakurai.
After traveling by plane Tosaki meets a former marine in order to learn more about Sato's true nature. Carter tells Tosaki about how he first met Sato in 1969 when training to become a marine. Sato was soon pulled out to join an elite team of soldiers. Carter met Sato again in 1976 in a mission to save a POW in Vietnam. They rescued him but during the mission Sato purposely fired a bullet to summon countless of enemies. This resulted him in losing his right leg and was dishonourably discharged.
Meanwhile Tanaka kills their 5th target thanks to information given to them by a police officer.
Tosaki meets with the rest of the group and confesses that the minister caved but they were still going to fight Sato regardless.
Tanaka returns to Sato to inform him that they killed the 5th target and asks who they should target next. Sato confesses to Sato that he is bored of the list and that Tanaka should take care of the rest without him. Tanaka meets up with Okuyama, who gives him the blue prints to the forge security building.
While Kei is being driven Kei tells Nakano that people don't change. The story shifts back to the the flashback of Sato's childhood where he was hit by his father. Sato's father tells Sato that life is precious and that he loves him after he caught Sato killing animals.