Satsuki Shinomiya

Satsuki Shinomiya (四ノ宮 那月 Shinomiya Satsuki) is a student of Saotome Gakuen from Class A, as well as a member of the duo group Black Crystal.

Appearance
Satsuki is a tall young man with blond hair that is wavy with one lock curling upwards on the top of his head and light green eyes. While he shares Natsuki's appearance, he has a stronger and more violent presence.

Personality
Satsuki is Natsuki's twin brother who has increased strength and whose personality is the dark side of Natsuki's. Satsuki acts as a body guard for Natsuki. Satsuki is solitary and doesn't usually like being around people. However, because he loves Natsuki, he has taken a liking to Haruka. He is unstable because of his very short temper and becomes extremely angry if he is ticked off. According to Syo, Satsuki has hospitalized all 50,000 of the people he's attacked who have offended Natsuki in some way. With his above average strength, it is almost always a disaster to have him around. Satsuki is a musical genius and composes amazing music whenever he gets the chance. In later seasons of the anime, Natsuki reconciles with Satsuki and he starts to become a bit more calmer.

History
Years ago, he and Natsuki used to play the violin and participated in many violin competitions with Syo Kurusu in their youth. When it came to composing, he was considered a "genius". In his youth, Natsuki was in love with his teacher and composed a song, titled "Satsuki" for her. However, she stole his composition and used it to make herself famous. Satsuki's feelings of anger and despair towards this eventually caused him to put the teacher in the hospital.

In the anime, Satsuki is shown to also be childhood friends with Syo, the three competing with each other in competitions. One day when Natsuki and Satsuki were 7 and Syo was 5, Natsuki chased Syo up a tower, trying to catch him; most likely in order to dress him up or something to that extent, with Satsuki trying to stop him. The three climbed to the top and Syo accidentally fell out of the tower window trying to escape and nearly fell to his death, but Natsuki and Satsuki grabbed him just in time. Syo then realized how high up he was and scrambled back up in to the tower saying he's scared; the whole ordeal caused Syo to develop a fear of heights, but the three didn't remember this until Shining Saotome brought the memory up through hypnosis on Syo.

Prior to meeting Syo, Satsuki and Natsuki used to live in France until they were five years old.

Trivia

 * Satsuki can be written using different kanji characters and can mean: Either as a given name or surname. 五月, "May" 早月, "early moon/month" 皐月, "swamp/shore", "moon/month"
 * Satsuki's surname Shinomiya means "four" (四) (shi) and "temple, shrine, palace" (宮) (miya).
 * Just like all the other characters, Satsuki has a designated theme color.
 * For Satsuki, it is yellow-green
 * He, Natsuki, and the Kurusu twins share the same birthday (June 9).
 * In the anime, he, Natsuki, and Syo knew each other since childhood, from being students in the same elementary school and often competing against each other in violin recitals.
 * Standing at 186 cm (6' 1"), Satsuki and Natsuki are some of the tallest members of the series.
 * They inherited their unusual strength from their father.
 * Their family home is on a farm.
 * During his childhood, Satsuki and Natsuki have lived in France and Hokkaido.
 * Since the incident, Satsuki quit playing the violin and specialized in vocals instead.