This technique was first displayed by Mu after his revivial by Kabuto this technique is to literally split the user's own body into two identical yet entirely independent duplicates of themselves. Unlike the Clone Techniques that only appear to be similar and not entirely, this ability is a instead a entire physical separation and so it doesn't require any hand seals to activate, making it a much more difficult technique and faster in comparison as a result. This also means that even if one is physically or mentally incapacitated, the other remains completely unaffected and as neither can truly be regarded as the original, the duplicates unlike clones cannot be dispelled. It was shown that the technique parent jutsu was the Shinju Fission Technique as it made its own physical duplicates.
The technique major weakness is while the user is split the user's power is half and as such any user is unable to use more advance techniques like Mu's Dust Release a very advance Kekkei Tota.