This fruit allows the user to stitch objects to flat surfaces. It is very useful in pinning people to the ground as demonstrated when Leo was able to restrain Robin. The user is also able to undo the stitches to the object, as seen as when Leo undid the stitches on Robin. In the anime, other dwarves were also seen undoing the stitches. However, the stitches do not harm its victim and do not appear to physically puncture the object. The stitches are strong enough to hold Robin down. The ability can also be used on steel, implying that the hardness of an object does not hinder the sewing process.
This fruit does not have any known specific weakness besides the general Devil Fruit weaknesses. However, it seems that a sewing needle is needed for the ability to actually work.
Leo basically uses this power to stitch and hold down his targets. He also uses this ability to support objects, during earthquakes, to make sure they do not fall. It can also be used to reattach severed limbs, although irregular wound edges may compromise its efficiency.
Haute Couture: Patchwork (高級仕立（オートクチュール） パッチ★ワーク,Ōto Kuchūru: Patchi Wāku?, literally meaning "High Class Sewing: Patchwork"): Leo stitches several objects or persons to his opponent. Then, by pulling the thread, he causes all stitched objects to converge towards his opponent, crashing into that one person to damage it thanks to his superhuman strength. "Haute Couture" is French for "High Sewing" and refers to the practice of creating custom-fitted clothing. It was first seen used against Jora, stitching all of her comrades and subordinates around her.
As with the Mato Mato no Mi (which was referred to as the "Mato Mato Curse"), this fruit has not yet actually been named in the manga. Unlike the Mato Mato no Mi, it has not been expressly confirmed to be a Devil Fruit. Leo referred to his "magic" as the "Nui Nui" power, notably in hiragana rather than the katakana used in all Devil Fruit names. Despite this, the name has the same repeated two syllable word structure as all other Devil Fruits, and the nature of the ability clearly points towards it being a Paramecia fruit.