Kasuga Igarasu is a fictional character from the anime and manga series 'Kimetsu no Yaiba' (Demon Slayer). Although not part of the main cast, Kasuga is depicted as a supporting demon slayer within the Demon Slayer Corps. Known for his quiet demeanor and strong sense of justice, he specializes in reconnaissance missions. Kasuga’s keen observational skills and loyalty make him a valuable asset to the Corps, often aiding Tanjiro and his companions during critical moments against powerful demons.