13 is a resident of the Hole and a regular customer at the Hungry Bug restaurant, where he is friends with owner Nikaido as well as other patrons including Vaux, Haze, and Jonson. He is around 25 years old. He has a disheveled appearance with dirty blonde hair that reaches the back of his neck, sunken eyes with small pupils and dark bags underneath, pointed teeth, and two red stripes on each cheek. He typically wears a striped hat, a worn jacket with spikes on the shoulders, a grungy t-shirt bearing the number 13 on the front, skinny pants, and a plaid skirt-like garment. His personality is marked by a laid-back demeanor, but he is also very quick to react with extreme emotions such as irritation, fear, and anger. He has a cowardly side and tends to shy away from danger. Early on, he shows a romantic interest in Nikaido, though this later simmers down into a more loyal friendship. When he learns that Nikaido is a magic user, he is notably confused and scared by the revelation. He is first seen eating gyozas at the Hungry Bug, which puts him at odds with Kaiman over the restaurant’s gyoza supply. He later volunteers to play on a hospital baseball team against the Heiwa Clinic Sharks, during which he asks Kaiman about his relationship with Nikaido and whether he would mind if he asked her out. After Kaiman leaves the Hole, 13 notes the Hungry Bug’s bustling trade thanks to Nikaido’s cooking. At Dr. Vaux’s birthday party, a mushroom monster attack teleports the group to the sorcerer En’s mansion, where En transforms 13’s head into a large mushroom, leaving him blinded and imprisoned for days. He is eventually freed and healed by the sorcerer Noi. He later joins a mission to find Kasukabe’s wife in the Hydra Forest, hoping to deliver a message to Kaiman about Nikaido’s capture. During the journey, he is injured by a magic user with a machete and hides in a closet with Vaux. He expresses relief and happiness upon finally returning to the Hole. Despite his fear, he persists alongside his comrades as an ordinary human from the Hole who is frequently placed in perilous situations involving sorcerers.