Zanjutsu (Kenji Hiroshi)

Zanjutsu (斬術, Swordsmanship; Viz "Art of the Sword"; Cutting Technique) is the fighting style for the, (i.e. sword fighting). Almost all have at least some level of skill in this field, with many, such as Kenji Hiroshi and Kusaka Kori, specializing in the art. It is particularly noteworthy amongst the Ryū Order, where the skills taught therein are integrated into the Wan'nesu.

Jinzen
The most necessary component of all Zanjutsu is  (刃禅, Blade Zen/Sword Meditation). Technical skill aside, Jinzen is the deciding factor in whether one can truly ascend to the plateau of a master. This is primarily because Zanjutsu is not solely the art of swordsmanship, but rather, the art of wielding a zanpakutō. The zanpakutō is a, one capable of thought, communication and feelings in the same way as other beings. This is because the zanpakutō spirits are, in fact, a physical expression of one's soul, alternatively regarded as the inner world (内世, Naisei) and are thus another portion of a Shinigami's power. Those who manage to synchronize enough with their zanpakutō spirit are capable of manifesting their and  states. In addition to attaining a slew of new abilities and powers, the Shinigami also grows in strength marginally as a result, evidently due to the connection both the user and zanpakutō possess.
 * ' (始解, Initial Release): The first released state of a zanpakutō. When one has communicated with their zanpakutō and learned their name, the user is capable of releasing a portion of the spirit's power and manifesting it in the physical world through employing the ' (浅打, Shallow Hilt) as a medium. For the most part, the Shikai of one's zanpakutō reflects the aspect of combat that the user is most proficient in, thereby increasing their overall power and skill marginally. An example of this is Shūhei Hisagi whom, upon releasing  against managed to completely overwhelm the Arrancar, despite his claims of being at Captain-level. This is a primary indication of a considerable increase in both spiritual energy output and overall skill, with the former best shown through Shūhei's explosively enhanced Kidō, as stated by Findorr himself.
 *  (卍解, Final Release): The second and final released state of a zanpakutō. It went initially under the name of Shinuchi (真打, True Strike) and the state inferred that you possessed an Evolved Zanpakutō' (進化した斬魄刀, Shinkashita Zanpakutō''). The primary concept of Zanpakutō's evolution is still present, in the form of the spirit changing in accordance to the wielder. Examples include and . The former's spirit rejected the power of  and accordingly did not allow him to tap into the zanpakutō's full strength — its name — whereas in the case of the latter, the Bankai had evolved due to 's experiences and gathered strength. Nevertheless, these examples highlight one distinct feature of Bankai: it is the penultimate strength of one's zanpakutō expressed completely in the physical world. It is because of this that the major requirement for achieving the state is the manifestation of the Zanpakutō spirit in the real world, and is also the reason for one's Shikai activation becoming seamless after its acquisition. Due to the zanpakutō being completely manifested in the real world, it accordingly represents the state at that point in time where the user is at their most powerful. One undergoes a five to tenfold increase in their ', because the entirety of their soul is laid bare. Consequently, the connection between a Shinigami and their Bankai is extremely close, to the point where, in the case of a mastered Bankai, any damage to the Bankai is reflected upon the user. For this reason, despite the grand explosive power that Bankai provides, it is also an extremely risky maneuver that should only be considered against opponents that one has no options left against. In hindsight, it is the greatest sign of one's mastery over Zanjutsu, for the soul of one's zanpakutō and their own soul have essentially reached perfect synchronization.
 * Shinzan (真斬, True Cut): Although not a released stage, the Shinzan is a technique which embodies the relationship between zanpakutō and wielder. It enables complete synchronization and, therefore, enhancement of the user's base abilities to the point where even beings with Lieutenant-level capabilities could easily skyrocket and perform on the level of a Captain.