: Umaru’s hard-working older brother who manages their household. He acts as the grounded foil to Umaru's eccentricities, often tasked with cleaning up after her and encouraging her to be more responsible.
: A hyper-competitive, boisterous classmate who views "Outer Umaru" as her primary rival. Real-Life Inspiration and Legacy Himouto! Umaruchan
: In public, Umaru is a "Mary Sue" archetype—a beautiful, intelligent, and talented student admired by everyone. : Umaru’s hard-working older brother who manages their
: A classmate with a fierce appearance but a shy heart who accidentally discovers Umaru’s "inner" form, leading to a unique friendship. leading to a unique friendship.