Itsuki has short light brown curly hair and golden eyes.
He appears to primarily wear a sleeveless tunic with light clothing underneath. Additionally, he wears thin leather gloves, leather boots, and a green hood-like cape attached around his neck and right shoulder.
The weapon in his possession is the Legendary Bow which was granted to him when he was summoned to another world.
He constantly behaves recklessly as a result of his excessive strong sense of justice. In addition of being egotistical, he also has a tendency to look down on others. His refusal to listen to other caused problems on several occasions.
During the first loop, Motoyasu's bizarre personality lost his credibility with all heroes - including with Itsuki. Leaving the castle with three companions, Malty approached Itsuki after being rejected by Motoyasu. After a warm welcome, he was given chain mail armor which she had stolen from Naofumi.
Early the next morning, Malty rushed over to Itsuki in a mess, claiming to have been raped by Naofumi. Ren and Itsuki assemble with the king in order to discuss the ordeal. Itsuki completely believes Malty while disbelieving Motoyasu's claims of being from the future.
In order to test his theory on how Time Reversal works, Motoyasu kill Itsuki immediately after being summoned.
After the four heroes were summoned, Motoyasu used his knowledge of the future and the other heroes to convince them that his was from the future. However, he was separated and forced to flee to Siltvelt with Naofumi before he could talk more with Ren and Itsuki.
However, unlike Ren, Itsuki did not take Motoyasu's warning to heart and slowly he was warped to be a tool for King Aultcray and Malty. Feeding into his desire to be a hero, King Aultcray and Malty gave Itsuki preferential treatment. One night, one of Itsuki's companions were killed by The Church of the Three Heroes and Itsuki was told that Naofumi was responsible. Soon after, he joined Melromarc's army to fight against Naofumi, Motoyasu, and Siltvelt. When Naofumi and Motoyasu tried to confront Itsuki, he was too far gone and there was no reasoning with him. Itsuki attacked but was easily defeated by Naofumi and Motoyasu. Seeing that Itsuki was easily defeated, his companion Mald immediately declared that Itsuki was a false hero and killed him before Naofumi and Motoyasu could stop him. This forced Motoyasu to reset with another time loop.
Information to be added later on.