Rioichi Cooper's book contains many secret sushi recipes, including one for his famous 'Ninja Roll.'
— In-game description[src]

The Ninja Cookbook is a treasure found in Turning Japanese of Sly Cooper: Thieves in Time. It is worth 120 coins and has a time limit of approximately 30 seconds to get it to the safe house before it disappears.


It is a metallic book that features an image of a fish on the front, holding a sushi knife and wearing both a toque blanche and brown ninja headband. On the right side of the book is a clasp for holding it shut. According to the in-game description, it is Rioichi Cooper's sushi handbook, and contains many sushi recipes and secrets invented by him.


The Ninja Cookbook is located on a boat on the eastern side of the map.