The Doa Doa no Mi is a Paramecia-type Devil Fruit that allows the user to create doors through anything they touch, making the user a Door Human (ドア人間 Doa Ningen). The doors they create can be created from any part of their body, from the palm of their hands to their whole body itself, and usually take the shape and form of the body part creating it. The doors remain as passageways anyone can pass through until closed completely. It was eaten by Blueno.
The fruit's first and foremost strength, as demonstrated by Blueno, is that it gives its user the ability to create a door on almost any solid surface so that they can enter through. This allows them and anyone else passage through the object no matter how thick or strong it is. Though this ability is normally used to gain free passage, the user can also exploit this in other ways, such as trapping an opponent's feet in small doors created underneath them.