As an 8-year-old human child in the Light novels prior to the Apocalypse, Mika appears wearing short jean shorts. He wears a white hoodie over a collared shirt. Sometimes, he is also shown wearing an over-sized jean jacket. He has short, wavy blond hair and blue eyes, which gives him the appearance of a foreigner. As a 12-year-old, being human livestock, Mika wears the standard livestock uniform. He wears the capri shorts and a hooded shirt. He is barefoot like the other livestock. In chapter 36 his eyes turns red after drinking Yū's blood.