Kisenshin

Kisenshin is a type of meditation practiced primarily by Hakuda practitioners, especially Masters and Grandmasters, but Kido Users get use out of it as well.

Overview
The art of Meditation has been around for many centuries, and is a practice to ease one's mind, body, and soul through the act of spiritual conditioning. Although an exact definition has never been coined, that's the closest thing ever given, given by Nemaiya Oetsu. Kisenshin, created by the aforementioned Kami, is an advanced version of normal meditation, taking the practitioner away from any realm, allowing them to reside for a lengthy time within the confinds of their own minds. Utilized primarily by Hakuda Masters and Grandmasters, the purpose is to put their mind and body at ease before and after a major Hakuda battle. It as the effect of not only blocking out all outside distractions, no matter how devastating, (albeit leaving them open to attacks by enemies), but also healing the wounds they've sustained during battle, albeit very slowly. This is also a method for Hakuda users to learn new techniques and improve their Hakuda powers ten fold, as it allows for absolutely no distractions whatsoever; whatever they learn in their minds, they will, without a doubt, always retain when they stop meditating.

Hakuda Kisenshin
Hakuda Kisenshin has been around as long as Hakuda itself, maybe even longer. It was first practiced by monks during the Pre Soul Society days, after Nemaiya Oetsu created it during his younger years; the practice of Kisenshin allowed them to obtain peaceful resolve within their souls, and fight with such fierocous power that it's said they gave birth to modern Hakuda Grandmastery. Some of the greatest Grandmasters, such as Shikyo Fushiawase and Nemaiya Oetsu, are even able to create a sphere around themselves with the energy that emits to protect themselves, but this is a feat that not many can accomplish. In order to become a Hakuda Grandmaster, mastery of Kisenshin is absolutely necessary.

Kido Kisenshin
In the realm of Kido, Kisenshin has only been used for a few hundred years; this version is even younger than the Gotei 13 themselves. A genius transition created by Joel Goldsmith, who's a Grandmaster of both Hakuda and Kido, it's meant to improve the user's overall spiritaul powers, since Kido is, put simply, the greatest of all spiritual powers. Many of the principles for Hakuda Kisenshin are present for Kido Kisenshin. While meditating, the user is in absolute harmony; it is, however, much easier to reach a state where the user is protected while in this state, since they're working with Kido after all, but does still require some effort. While in this state, the user can learn as much Kido as they wish to, afterwhich retaining all of that newfound knowledge and power when they stop meditating.

Zanjutsu Kisenshin
Although not widely practiced, Zanjutsu Kisenshin does exist, as an alternative to the Jinzen; this is the youngest of them all, having only been around for roughly ten years.