In childhood, Udon was distinguished by a calm, unhurried, and somewhat phlegmatic disposition. He almost always looked sleepy and rarely showed strong emotions. His favorite activity was mathematics — he often solved problems even during lessons. Despite his quiet character, he was a loyal comrade and followed Konohamaru everywhere. He rated his ninja skills lowly and considered himself a failure, as the Clone Technique was given to him with difficulty. He treated the 'boss' Naruto with great respect and tried to imitate him in everything. He was not quarrelsome and preferred to stay away from conflicts. However, at the right moment he did not get scared and did what his elders required of him. His good-natured and easygoing character made him an inconspicuous but reliable member of their little company. He rarely spoke, but listened attentively.