Kadoyan is an overweight, bald man with fair skin and grey hair on the sides of his head. He has round eyes, a large nose, and thin eyebrows. He wears a red, short-sleeved shirt that has a color.
Kadoyan is a kind and welcoming man who is comfortable chatting with strangers like the Straw Hat Pirates, telling them about the Firework Festival without knowing them prior. He was worried about accidents after Kodama's parents were killed in a firework launch malfunction.
One year before the Straw Hat Pirates arrived at Fireworks, Kadoyan witnessed the firework accident that killed Kodama's parents.
Kadoyan noticed the Straw Hat Pirates looking at signs for the Firework Festival and asked them if they were visiting for it. He and a merchant he was purchasing food from briefly explained the festival's history and that an old man and a young girl. Usopp ran off to ask the firework makers for gunpowder, and Kadoyan worried about an incident similar to last year happening. The merchant told him not to talk about it with the crew, as they were only there to enjoy the festival.
- One Piece Anime — Episode 134, Kadoyan tells the Straw Hat Pirates about the Firework Festival.