The fifteen-year-old protagonist of the story, Rin is the son of Satan born from a human woman and is the inheritor of Satan's powers. Rin can tap into the power he has inherited from Satan through the use of a demon-slaying katana, called Kurikara or Koumaken. The sheath acts as a portal to Gehenna (the demon world) which when drawn returns Rin to his demon form. While in his human form, Rin exhibits a number of physical traits that are signs of his demonic nature, such as sharper-looking teeth, slightly pointed ears, and a black, fur tufted tail (which he keeps hidden in his shirt). As a demon, Rin gains two blue flames that float above his head, long, elf-like ears, and his eyes turn bright blue. In both forms Rin can almost control his destructive bright blue flames, the trademark sign of Satan. However, when he draws Kurikara, the magnitude of the flames dramatically increase and often leads to Rin being "consumed" by his own flames and losing his mind. Rin also has a demon Familiar Cat Sith, Kuro, who was initially Father Fujimoto's. He is surprisingly good with his hands, and his cooking repertoire includes all kinds of Japanese and Western foods (home cuisine). (Source: VIZ Media)

Hanako is one of the main trio of Asobi Asobase. Along with Olivia and Kasumi, she makes up the Pastimers Club. She is extremely energetic and often drags her two friends into her pace by playing strange games at school, which often gets the three of them in trouble. Hanako is prone to anxious thoughts which often trail off in bizarre directions. Her family is shown to have some of wealth or noble connection as she is able to obtain objects upon request.