Mitsuki

Mitsuki was created as a synthetic human by Orochimaru, being cultivated from the same embryo as at least one older "Mitsuki". Just like his "brother", Mitsuki was named after "Tsuki" (杯, Literally meaning: Vessel) and the sixth sign of the Chinese zodiac calendar, "Mi" (巳, Literally meaning: Snake). Orochimaru, as Mitsuki's "parent", wanted Mitsuki to find his independence, having concocted a complex plot for Mitsuki to do so. On Orochimaru's sixth attempt of the plan, each time erasing Mitsuki's memories of the previous, Mitsuki mastered Sage Transformation and decided to rebel against his "parent" and "older brother". He left their company and set out to forge his own destiny himself, now going by the name "Mitsuki" (巳月, Mitsuki) by replacing the second character with "Tsuki" (月, Literally meaning: Moon). Upon discovering the existence of Boruto Uzumaki via a gift from Orochimaru, Mitsuki decided to go to Konoha and befriend him in order to find his own path in life.

Mitsuki has a very calm and matter-of-fact demeanor. He is generally seen very cheerful, if not indifferent, the situation at hand. While not confrontational, he freely speaks his mind in any situation and does things at his own pace. He is also shown to have a sharp wit, being well-read and observant, showing advanced knowledge in mathematics. He's quite close with Boruto, caring about his opinion above that of most others. Seemingly stemming from his harsh upbringing with Orochimaru, Mitsuki is very vicious in battle, showing no restraint and willing to kill his foes without hesitation. He is also very driven and committed when given a task, as when he was ordered to kill someone, he would not waiver regardless of who it is. During his time at the Academy, it doesn't seem as though he had much of a friendship with Sarada Uchiha until they were assigned to Team Konohamaru.

Despite not revealing much about his origins or parents to them, Mitsuki cares about his teammates, Boruto and Sarada, to the point where he never hesitates to rush to their side when they are in danger or in need of assistance. Mitsuki has a high opinion of Boruto as the son of the Seventh Hokage and the grandson of the Fourth Hokage, and Mitsuki believes Boruto is destined to become Hokage himself one day, despite hearing Sarada's repeated declarations that she will be Hokage.

Mitsuki seems to admire Naruto and Sasuke Uchiha due to them both being high-ranked shinobi and tells Boruto and Sarada how his parent told him their fathers are rivals who can fight equally. Mitsuki also holds a great deal of admiration for his father as well as confidence in his abilities, to the point of being naive, as shown when he boasted to Boruto and Sarada that Orochimaru was even more powerful than both of their fathers.

(Source: Boruto Wiki)