Rei Sakuma is a charismatic and mysterious character from the multimedia project Ensemble Stars!, which includes games, anime, and manga. He is a member of the idol unit UNDEAD, known for their rebellious and dark aesthetic. Rei, often depicted with long black hair and a captivating presence, is a vampire-themed idol, adding a supernatural element to his persona. Despite his seemingly aloof demeanor, he is deeply caring towards his unit members and friends, often taking on a protective role. Rei's complex personality and unique style make him a fan favorite.