Board Thread:Rebirth: Applications/@comment-2001574-20141106154832/@comment-2001574-20141108213653

It's mostly because of how it came to be during its creation. But over the centuries, natural energy was no longer needed for it to function, just the physical energy. The primary reason why I went for dojutsu was because that's how it was the first time. Anything that alters the properties of the eyes probably falls under dojutsu, no doubt.