Shinomiya Natsuki and Satsuki

Trivia The name Natsuki means "it" (那) (na) and "moon" (月) (tsuki). Natsuki Shinomiya's surname means "four" (四) (shi) and "temple, shrine, palace" (宮) (miya). Like all members of SAN RISH, he has a designated theme color. For Natsuki, it's yellow. Natsuki tends to use strange, often unsuitable, ingredients in his cooking. Curiously, he isn't bothered by his own cooking. In the manga, Natsuki is very aware of Satsuki's existence, unlike in the anime where he only has a vague feeling that someone is looking out for him. He and the Kurusu twins share the same birthday (June 9). Official Natsuki & Syo promos sometimes point this out as well. In the first episode of the anime, he could be seen reading a cookbook. A running gag in the anime is that whenever he remembers Elizabeth (his dog), he thinks of Haruka because of her resemblance to his dog. In the anime, he and Syo had known each other since childhood, being students at the same elementary school and often competing against each other in violin recitals. At 186 cm (6' 1"), Natsuki is the tallest member of SAN RISH. He inherited his unusual strength from his father. His family home is on a farm. During her childhood, Natsuki lived in France and Hokkaido. Since the incident that gave rise to Satsuki, Natsuki stopped playing the violin and specialized in the viola.

History Years ago, he played the violin and participated in numerous violin competitions with Syo Kurusu in his youth. He was considered a "genius" when it came to composing. In his youth, he was in love with his teacher and composed a song for her, titled "Satsuki." However, she stole his composition and used it to become famous. Her feelings of anger and despair over this eventually led to the creation of her other self, Satsuki.

In the anime, Natsuki is shown to be Syo's childhood friend, and the two compete against each other in competitions. One day, when Natsuki was 7 and Syo was 5, Natsuki chased Syo up a tower, trying to catch him; most likely to disguise him or something. The two climbed to the top and Syo accidentally fell out of the tower window trying to escape and almost fell to his death, but Natsuki caught him just in time. Syo then realized how high up he was and ran back up the tower saying that he was scared; the whole ordeal caused Syo to develop a fear of heights, but the two did not remember this until Shining Saotome elevated the memory through hypnosis on Syo.

Before meeting Syo, Natsuki lived in France until she was five years old.

Personality Natsuki has an extreme fondness for cute and small things, which leads him to take an immediate liking to Haruka Nanami, stating that she resembles Elizabeth (Natsuki's dog). At the beginning of the second season, he sees her as a little fairy.

She enjoys cooking, but doesn't realize that everything she makes is disastrous, often causing her reluctant taste testers (most often Syo Kurusu) to faint or choke in disgust.

He also appears to be very foolish and naive at times, although he shows great insight in other circumstances.

She suffers from a split personality disorder called Gemini syndrome, and her other side is called Satsuki, who has greater strength and whose personality is Natsuki's dark side. Her Satsuki personality manifests whenever Natsuki's glasses are taken off. In this capacity, Satsuki is supposed to work as Natsuki's bodyguard. The only way to get Natsuki back is to put glasses (of any kind) on her. Once the glasses are put back on, Natsuki has no memory of being Satsuki or what she did while Satsuki was in control.

Satsuki is a loner and typically doesn't like being around people. However, since he's also Natsuki, he's taken a liking to Haruka. He's unstable due to his very short temper and gets extremely angry if he's angry. According to Syo, Satsuki has hospitalized the 50,000 people he's attacked. With his above-average strength, he's almost always a disaster to be around. Satsuki is a musical genius and composes incredible music whenever he gets the chance, which explains why Natsuki finds that music just appears to him. In later seasons of the anime, Natsuki reconciles his Satsuki personality and becomes whole again.