Rioichi Cooper is the first ancestor encountered by the Cooper gang in Sly Cooper: Thieves in Time(Sly 4). Rioichi was part of the Cooper Clan in Japan during the 16th and 17th century. Rioichi was the Cooper who invented the Ninja Spire Jump and the Leaping Dragon technique. The Ninja Spire Jump is a move used all throughout the Sky Cooper series, and first appears in the Thievius Raccoonus in Sly 1, when Sly successfully retrieves Rioichi's pages. Not only was Rioichi a master thief, but he was also a master chef, and owned a sushi restaurant in Japan.
One day, as a child, Rioichi went fishing and caught a huge white shark. Rioichi was about to kill the shark when suddenly, he noticed a birthmark on the shark's chest. This birthmark resembled the Cooper Clan's symbol. Rioichi felt this was a sign, and decided not to kill the shark. The shark, eternally grateful, swore his loyalty to Rioichi and served as his mount during war. They were very successful in their battles, receiving great rewards from the Emperor.
As years passed, the shark began to grow too old to fight anymore. The shark knew his end was near, and also was aware of Rioichi's dreams of starting his own sushi house. Knowing this, the shark asked Rioichi to honorably end his life, and offered his body as Rioichi's start to his sushi restaurant. Rioichi accepted, although obviously filled with sadness. However, the shark's honorable sacrifice gave a great start to what would be a very successful sushi restaurant for Rioichi. This sushi shop provided a great cover for Rioichi's thieving exploits.