Takigakure, the Village Hidden in the Waterfall, was one of the earliest hidden villages to be founded but its military force and economic power was never great enough for it to be recognized like the Great Five. However it has also never been successfully invaded and is the only minor hidden village to have held a Tailed Beast.

The founding clan of Taki was dedicated to guarding and preserving a centuries-old tree that grew in the heart of the Land of Floods. It was only by taking advantage of the tree’s unique properties that they survived the Warring States Era against enemies more powerful than themselves. And it was the promise of that power which allowed them to forge an alliance with the surrounding clans to build the hidden village.

When sap extracted from the tree is ingested as a part of a medicinal elixir, it stimulates the chakra pathways within the body to forcibly open the Eight Gates that restrict chakra flow as a self-defence mechanism. The more of this elixir a person drinks then the more Gates are opened and the more powerful they become all the way up until the Eighth Gate.

This makes them incredibly dangerous as they can tap into a level of strength far beyond their normal abilities, allowing them to fight and defeat ninja superior in skill and numbers. It is this elixir, more than anything, that has allowed Taki to remain uninvaded through three great wars despite being on one of the minor nations acting as a buffer between the Lands of Fire and Earth.. And that is why it was unofficially known as the Hero Water.

However opening the Eight Gates is a forbidden jutsu because of the immense physical stress that can cripple or kill the person using them even before reaching the final gate. Learning to open the Eight Gates requires a body strong enough to withstand that power in the first place while those who simply drink the Hero Water aren’t trained to handle it. So not only do they sustain the usual damages inflicted by the Gates in a body that typically cannot withstand it, they suffer even further because they were forced opened unnaturally in the first place.

The drinker also has no control over the Gate itself so it could remain open when they no longer need it or close against their will which is likely to put them in danger during combat. More often than not, those who drink the Hero Water end up killing themselves along with their enemies.

The reason the sap contains such incredibly properties is because the tree’s roots have dug so deep into the earth that it reached nexus of dragon veins which allowed it to directly feed on the planet’s chakra, providing it with a powerful lifeforce beyond most others. When a ninja clan learned of this, they performed numerous tests on the tree to discover if it had gained any unique properties and discovered the powerful effect that the sap can have on the human body. Experiments with other special ingredients allowed them to refine the ideal recipe to maximum its potency.

Hero Water is restricted to the jounin who can be trusted to wield its power responsibly, likely survive the effects and prevent its secrets from falling into enemy hands. But only those directly involved in its development, the village elders and the village leader are aware of the elixir’s true composition. In addition to the usual genjutsu blocks and traps used to resist enemy interrogation, these jounin are deliberately misinformed about its contents to help deceive foreign intelligence.

That tree was also the reason that Taki was the only one of the minor hidden villages to have possessed a Tailed Beast. Like Suna, they captured the Seven Tailed Beetle themselves and were able to bind it to the village by creating a sealing formula powered by the chakra drawn up from the dragon veins through the three. Doing so, they were able to entrap the beast within a prison so strong that escape was impossible.

But when the First Hokage started to capture the Tailed Beasts with his Wood Release, Taki grew paranoid and sent their strongest ninja Kakuzu to assassinate him then retrieve his body for them to harness its power themselves. However he failed, surviving only by faking his death after he was completely defeated by Hashirama, and returned to his village only to be locked away and villified for that failure.

Enraged by this betrayal, he escaped his imprisonment, slaughtered the village elders and escaped with the kinjutsu scroll for Earth Grudge Fear so that no-one else could gain the same ability as himself. Kakuzu became something of a bogeyman for the hidden village as he unnaturally extend his life and viciously slaughtered any waterfall-nin he encountered for decades.

It was perhaps the loss of this shinobi and their kinjutsu that stopped Taki from rising up as one of the Great Hidden Villages in the future.

Taki remained standing through the following Shinobi World Wars and its ninja take great pride in never being successfully invaded. But the Third Shinobi World War struck at a time when manpower was at an all time low for every nation, forcing the smaller ones to undertake extreme measures to survive. Takigakure chose to give their chuunin and even some genin doses of the Hero Water on critical missions to prevent their small country from being overwhelmed by the superpowers of the land.

The gambit was successful in protecting their home but left Taki weaker than it had ever been for years after the war due to their crippling casaulties and minimal supply of Hero Water. They were possibly the weakest of all hidden villages which they tried to hide from enemies and allies alike. That caused them to finally follow the precedent set by other villages to create their own jinchuuriki instead of merely keeping the Seven Tails as a deterrent against invasion.

However, they lacked the experience and knowledge to properly develop and control their jinchuuriki. They went through several hosts and suffered a number of rampages that caused greater loss of life and destruction of property before finally finding a measure of success with Fuu.

Although she showed promise by not losing control of the beast, it was too little too late for most of the surviving shinobi. So many had lost friends and family to it that no one trusted her or could even look at her without seeing the monster within. Like many other jinchuuriki, she was hated and feared by her own comrades. When Akatsuki came to capture her, no-one was willing to risk their lives to come to her aid – as futile as the effort might have been – so she was ultimately defeated and her beast was extracted.