Niju Niju no Mi, Model: Heart

The Niju Niju no Mi, Model: Heart ( 二重二重 ) is a Paramecia-type Devil Fruit, in which the user is able to get a second heart being in his or her body. Niju for “Double”, in both Viz Manga, and the FUNimation dub, it is called the Double-Double Fruit, Model: Heart. This fruit was originally traveled throughouth most of the new world on a trading ship, however it was attacked by a group of bandits. The fruit was taken back to thier own hideout, however after the Marines had captured and executed the members. The fruit was put into the hands of Necrid Bagans, but then as a payment to Hakushin Okashi for research and information on the revolutionary's movements. It then made its way through the revolutionaries and now it is unknown to where the fruit is.

Strengths
The main strength of this fruit activates when it enters the user body, the fruit will turn into a second heart. But finding its place in the right side of the chest, basic the user has a second heart that beats and pumps blood throughout the body like the first one. But the blood flow and such increases ten fold, because of two hearts within the users body. The user can have an increase of speed, strength and many other attributes because of the blood flow increasing double.

Weaknesses
This fruit is almost like an insurance policy as well, if the user suffers from a heart attack or something with the first heart. The second one will take the place of the first one, however there is a few more weakness to this fruit. The next being is that if the user is stabbed in the heart on either side. The other one will replaced the damaged one, the damaged one will just remain the body. However, an advantage to this is the user will have a longer life because of two hearts. So if nothing happens to the first and just gives out naturally. The second one will take its place and the user will live longer. The user will suffer the standard weakness of the devil fruit as well.

Usage
This fruit is neither an offensive nor defensive one, basic it just allows the user to get a second heart along with the first. They beat simultaneously of course, this gives a great increase to a few things. The first being that oxygen to the body will travel twice the speed of a normal man. The users injures will heal faster because more white-blood cells will arrive at the wound or such faster. The user will decrease their own chances from diseases and such, because of the white blood cells going throughout the body. However, the full use of this fruit has not been revealed yet.