Retso was a wandering chef, traveling with his daughter, Shun Min, aspiring to find the fish needed to replicate the legendary "Mythical Fish Sashimi" his cooking master had once prepared for him. Retso was a specialist in fish dishes, wielding dual knives in order to give himself greater speed and control over his technique. His search for the proper fish for this legendary dish led him to the rivers of Falena, eventually taking a job in Raftfleet.
At Ceras Lake, the Prince of Falena would catch what could only be described as a "strange fish" but was, in actuality, the rare fish needed for Retso's Mythical Fish Sashimi. When prepared, however, the resulting dish tasted awful, Shun Min not even being able to finish her serving. Puzzled by the disparity in what he had prepared compared to his master's work, he would join the Imperial City Recapture Army in order to investigate the matter further at Ceras Lake.
While serving in the Recapture Army, Retso bounded with Logg, another father in the army, about their daughters. Retso felt a great deal of pride for his daughter Shun Min, who he considered very spirited and quite lovely, but felt guilt that ever since her mother had died, Shun Min had stopped trying to be a kid, and instead tried to act all grown up simply to spare him any trouble, making him feel like an idiot father. Many in the army enjoyed Retso's dishes, especially Nikea, although she sometimes wished Retso would involve more meats and less fish. The detective Oboro considered Retso's knife handling and presentation a sheer work of art, especially when it came to dealing with his specialty, sashimi.
Retso continued to study his master's Mystical Fish Sashimi, making some progress during the war, noting that the secret may have nothing to do with the fish at all. Following the end of the Sun Rune War, Retso discovered the secret of his master's dish, but, deciding it was best kept a secret, never said a word on it for quite a long period of time. He would be approached by Jinkai and would become a founding member of the Black Dragon Group.
Gradually, Retso would lose his way, becoming influenced by Jinkai's Dragon Plan. It was the death of Shun Min, which he blamed in his grief on her lover, Hai Yo, that led him to fully support Jinkai and use his master's technique to further their goals.
Retso, now known as the White Tiger, was one of the four lords of the Black Dragon Group and was Hai Yo's 9th and 11th challenger at the New State Army Headquarters. He attempted to wrest control of the Moon Bird Recipe from Hai Yo by defeating him in a cook-off.
He easily defeated Hai Yo and gained the recipe but it was quickly revealed he had used hypnosis to convince the judges to award him perfect marks. This hypnosis was implied to be the true secret behind the great taste of the Mythical Fish Sashimi he had long searched for. His deception uncovered, Retso would agree to compete fairly only to be defeated by Hai Yo. Realizing his mistake and regaining his true pride as a chef, he would support Hai Yo in his final cook-off against Jinkai.
- Announced as "Retso of Byako", the phrase is more correctly translated as "White Tiger Retso."
- Gensosuikoden Encyclopaedia (ISBN 4-575-16297-3), page 315
- Gensosuikoden Kiwami Encyclopedia, page 688