Full name is Natsume Sakasaki. Natsume is a 19-year-old male, 171cm tall, and weighs 54kg. He has an asymmetrical red bob with white streaks, where only the left side is long. He has cat-like, sharp eyes with golden irises. Natsume is mischievous, sly, sarcastic, and enjoys teasing others. Despite this, he is fundamentally kind and perceptive of others' feelings. He is usually the one supporting those around him. He balances his life as a fortune teller and an idol. He is the leader of the male idol group 'Switch,' consisting of himself, 20-year-old Tsumugi Aoba, and 18-year-old Sora Harukawa. As a child, he briefly attended an idol training school run by Tsumugi's parents; at his mother's request, he dressed as a girl and was known as the 'mysterious genius beauty Natsume-chan.' This period remains a dark history for him, and perhaps because of habits formed then, he is sometimes told he acts like a girl. He cannot swim and does not enjoy physical activity. He often speaks and acts mysteriously but is a sincere hard worker. He dislikes noise and prefers to be alone, so his social circle is small and he avoids being tied down. He experiments with chemical compounds to design stage effects for idols or gives fortunes using a crystal ball. He is cranky, poor at expressing himself, and tends to hold grudges. The only person he treats with physical violence and harsh words is Tsumugi. Since he hasn't fully forgiven Tsumugi for his past mistakes from high school, he frequently lashes out at him, but in reality, he cherishes Tsumugi deeply. Natsume is the one who taught the emotionally detached Tsumugi about pain and empathy, and his harsh behavior is partly due to his shyness in dealing with him. His verbal abuse is usually triggered by Tsumugi 'asking for it'—Tsumugi insists on staying by Natsume's side as a friend, claiming it would be selfish to leave out of guilt, yet he constantly lectures Natsume. While Tsumugi's gentle lectures are logically correct, Natsume's mental world operates on a different level from his peers; Tsumugi fails to understand this and treats him like a young boy who needs looking after, which makes Natsume resort to his fists. Whenever Natsume is cold to Tsumugi, Sora—who can see human hearts as 'colors'—routinely comments, 'Master really likes Senpai~'. Natsume calls Tsumugi 'Senpai,' but very rarely calls him 'Tsumugi-niisan.' Natsume calls Sora 'Sora.' Sora calls Natsume 'Master.' Natsume treats Sora with unconditional kindness and warmth, as if he were a different person. Natsume always uses informal speech. Sora and Tsumugi always use polite speech. Sora calls Natsume 'Master' and Tsumugi 'Senpai.' Tsumugi calls Natsume 'Natsume-kun' and Sora 'Sora-kun.'