Zenitsu Agatsuma is a major character in the anime series Kimetsu no Yaiba, also known as Demon Slayer. He is a member of the Demon Slayer Corps and a companion of the main protagonist, Tanjiro Kamado. Despite his timid and cowardly nature, Zenitsu possesses remarkable lightning-fast swordsmanship skills when unconscious or asleep. His character development showcases a transition from being petrified of demons to gaining confidence through his dedication to protect his friends. Zenitsu's comedic relief, coupled with his fierce loyalty and hidden strength, make him a beloved character in the series.