Iriya (入谷, Iriya) is the chief of an Itsuwaribito company. With his childlike appearance, he disguised himself and entered the Village of Orphans to gain inside information about it. He killed everyone in the village except Utsuho Azako.
Iriya has short hair and fair skin. He wears a yukata along with sandals. When he betrayed the Village of Orphans, he was shown with a knife, but it is unknown to whether he had it hidden in his yukata.
For most of the story, bandages cover his entire body and the left side of his face due to the injuries sustained from one of Utsuho's bombs. He wears a yukata over this bandages and hangs a japanese sword on his left side.
Although he can appear innocent to trick others, his colors often reveal themselves in the form of an evil/slightly insane grin.
Iriya has a twisted personality due to his past. Since his family was murdered due to one of his lies, he felt that lying was all he could ever do. Iriya views everyone else as fools because they easily fall for his tricks. He often uses others as tools and has no qualms if others die in his schemes.
The only person Iriya likes is Utsuho Azako. In fact, Iriya's obsesses over Utsuho to the point of wanting to kill anyone Utsuho is close to. This obsession drives most of Iriya's actions throughout the story, from looking for the nine treasures to killing others. As twisted as his methods are, Iriya truly wants Utsuho to be his friend since they both share a similar past. Unfortunately, he believes that everyone else around Utsuho are 'scum' who could never understand Utusho the way he does, and so he often tries to kill them.
When he was young, Iriya was an innocent child who loved his family. However, one day he got into a trivial argument with them. While still angry, he goes out on a walk and meets some strangers who ask if anyone was at home. To take a small revenge on his family, Iriya lies and tells them that no one was home. He believed that these strangers were business partners of his father and hoped that his small while lie would cause his parents some distress. When he returned home, however, he discovers his entire household had been murdered by the strangers. To his horror, Iriya finds out that the strangers he met on the road were actually burglars who stole from places when people weren't there. They came to Iriya's house while believing Iriya's lie that no one was there. When the burgulars did find people there, they had to fight and kill Iriya's family. Iriya continues to blame himself for his family's death. This caused his personality to warp and lead him to believe that lying was all he was good for.
Iriya has high intelligence and often fights using both his impressive skill with the sword and trickery. While he is physically stronger than Utsuho, he is not as smart as him, as shown by how Utsuho is able to see through most of his tricks.
All of his weapons are either concealed or contain an extra 'trick' to them.
His sword conceals a smaller trick sword. He can also control his swords with the strings attached to them. He has even at one point put an explosive inside one of his swords so that he could detonate it after throwing it.
He has sandals with spikes at the bottom. These spikes are laced with poison.
- The name "Iriya" is a type of Japanese flower that means "Within the valley".