Baku

Baku is Johei's first Demon. He is a low level skill demon that has an unending appetite and little to no skill in battle. Throughout the series he is mainly a form of comic relief.

Baku first showed up in the first chapter as a demon eating cashews in the kitchen of Boite a Nourriture, a French restaurant where Johei had fought his first demon, Slime. Despite not showing any real hostility until provoked, Baku presented himself as no real threat. Through an intense negotiation process that involved him asking Johei if he has cable, Baku agreed to become Johei's demon. Upon arriving home, Baku stole Johei's bed, and used his Dormina spell to knock him out.

Chapter 2 started out focusing on the relationship between Baku and Johei, which was strained because Baku had no respect for his summoner. Gouto decided to try and get the two to work together by blind-folding them and having them help each other across a yard full of bear traps and land mines to receive a pie.Baku ended up stepping on the first possible mine, causing him to feel even more animosity towards Johei. However, upon hearing that Johei had been kidnapped by a powerful demon, Baphomet (a story made up by Gouto who in reality had tied Johei up in the closet) Baku rushed off to rescue him. According to Baku's own narration, he had been distracted by the movies, zoo and paintball, but ended up running into Baphomet at an old construction site (a direct nod to the site from the actual games) Johei was originally hesitant to go after Baku, but was guilt tripped by Gouto into helping him. Johei's rescue attempt however falls flat as Baphomet nearly kills both of them. As the two of them were about to be killed, they finally reconciled and decided to get along. Fortunately, Tanuki came along soon and rescued them. On the walk back to his house, Baku decided that he would try to respect Johei more and let him sleep in his own bed that night.

During the Juichi arc (Chapter's 3-5) Baku mainly helped out in battle, and had a slightly heated rivalry with Blizzard, Juichi's Jack Frost. After his initial encounter with Blizzard, he and Tanuki talked about what they would do. Baku says that no matter what, they should stand by him and fight. The next day, Baku saved Johei from being burnt by a trap that Inferno had set. While explaining what happened, Baku convinced Johei into treating him to Korean Barbeque, where Baku first explained to Johei that someone was trying to kill him. Chapter 4 is where Baku first demonstrates his ability to transform into someone after he ingests part of their body when he reveals that he had disguised himself as Ema in order to be kidnapped by Blizzard. (Gouto had stolen a strand of her hair earlier and tricked Baku into eating it by putting it on a cupcake) After Inferno defeated Tanuki, he went after Johei. Baku tried to help by covering Inferno's eyes but was shot in the back by Blizzard who had just recovered. Baku and Blizzard had a quickly heated fight where he successfully put Blizzard to sleep and was about to finish him off when he was shot in the back again by Inferno. When he was on the ground, the two brothers initiated their special attack on Baku which involved freezing his entire body and then shattering Inferno's lantern on him. Baku was critically injured from this and unable to act for the remainder of the arc. In Chapter 5, Baku is bed-ridden and requests that he be given ice cream because his soup is too hot.

In Chapter 6, Baku is feeling better and moving around. The night that Tanuki and Johei spent together, Baku revealed the next morning that he has started sleeping in the kitchen because "The humming of the fridge makes me warm in my belly..." which resulted in him not knowing what actually happened. Later, Baku is in the park eating Takoyaki when Johei asks him if he'd seen Tanuki. After Tanuki flees, Johei runs into Baku again whose sneeze accidentally casts Dormina and knocks Johei out for several hours. At the end of the Chapter when it is revealed the entire thing had been a farce put together by Gouto, Baku reveals he was the only character not really in on the plan.