Very little is known about Izo's personality, but through several different appearances and gestures. Most of the time he seems to have a calm and serious composer, he seems to go into battle with a calm mind and a steady finger. Izo has shown to have a great love for his crew and friends, which are his Nakama.
Revealed, because of a comment that Kojiro making to him about just what lengths he is willing to go, trying to break his spirit. Izo seemed to have also got angry whenever this was asked, because he had snapped out and replied back to go to hell demon boar. So sometimes Izo has lost his cool whenever the subject of the whitebeard crew or his nakama are brought into it.
After Whitebeards death and the attack by the Tyrant Pirates, Izo was captured by Kojiro. He was put into chains and now he is Kojiro's personal sake boy, often calling him them and forcing Izo to pour his drinks. Of course Izo is greatly upset at this and has tried many time to escape or such, but with the Zaimon Drug in his system. He couldn't do a thing and now Izo sits and waits for his chance to escape with the rest of the captured Pirates.