Mitsuki has a very calm and a matter-of-fact demeanour. While not confrontational, he freely speaks his mind in any situation. He is also shown to have a sharp wit, being well-read and observant.
Mitsuki 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.