|Family||Mondo Owada (Younger Brother)|
|Game||Dangan Ronpa: Trigger Happy Havoc|
Daiya Owada (大和田 大亜 Ōwada Daiya) was the founder and former leader of the Crazy Diamonds, Japan's largest motorcycle gang. He died on the night of his retirement during a motorcycle race between him and his little brother, Mondo Owada. He died to save Mondo, who had been driving too recklessly in an attempt to win the race, and would have been ran over by a truck if not for the intervention of his big brother. Daiya's dying wish was for his little brother to lead the gang in his stead, and to not let it fall apart.
Daiya Owada has black hair and appears wearing a white coat, white pants, and white shoes. The back of the white coat has the symbol of the Crazy Diamonds, which is a diamond with the name of the gang, “Crazy Diamonds”, around it.
Daiya was Mondo's older brother, who founded and led the Crazy Diamonds biker gang up until the day of his death. He and his little brother were participating in a motorcycle race, and Mondo became reckless while he was attempting to prove himself to the gang and Daiya. He sped into the wrong side of the road, and was about to crash into an oncoming car. Just before he was struck, however, Daiya pushed him out of the way, knocking him to the side and taking the blow from the car himself. He died in Mondo's arms, telling him to not let the gang be broken up. It was a “promise between two men”, which Mondo did his best to keep. When this secret is finally revealed, Mondo explains how guilty he feels for not only killing his brother, but for not being able to uphold the last promise he made to Daiya.
- “Whoops, bro... I slipped....”
- “Promise me... Don't let the gang break up..... It's a gang 'You and I' made together, after all... M... make me a promise... A promise... between... two men.....” (to Mondo Owada)
- Daiya and Mondo's names, when put together in order of older brother, and then younger brother (in the gang, first leader, and then second leader), mean “diamond” (ダイヤモンド). This is connected to the name of their motorcycle gang, which is the "Crazy Diamonds".
- The name of the gang ("Crazy Diamonds") is actually a reference to the character Josuke from Jojo's Bizarre Adventure whose stand name is "Crazy Diamond."
- Daiya along with Mondo both make an appearance in another Spike Chunsoft game, Kenka Banchou Bros: Tokyo Battle Royale.