Born as an orphan, Kabuto Yakushi was taken under the tutelage of Orochimaru, one of three great Sannin. It was from Orochimaru who taught Kabuto biology, evil, medicine, and ninja arts. Kabuto is very analytical and methodical thought his own ego can tend to get in the way of plans. He is critical of others but also polite at the same time. By his own admission, Kabuto is an introvert, however he is confident in himself at most all times.