The kata's focus is the idea of changing disadvantage into advantage by strong and courageous response, switching blocks and differing degrees of power.
The feeling of kata should be precise, with fast execution of technique and attention given to appropriate balance between speed and power.
One of the leading theories regarding the origin of Passai relates to the lion dance performed in Fujian Province.
However, the 1973 translation of Karate-do Kyohan lists Funakoshi's explanation of the form name as "Breaking through an enemy's fortress.
[citation needed] The Okinawans did not have a clear definition for the name "Passai" for Funakoshi to translate into Japanese, so he substituted it with a similar-sounding kanji, "Bassai".
This is thought to be in reference to the power with which the kata should be executed, emphasizing energy generation from the hips and waist.
Tachimura Passai is considered a closed door kata however purposefully altered versions of it exist on Youtube.
This version starts with Sasae uke then a step back followed by a spin and punches with sagurite kamae.
Tachimura Passai contains many deadly techniques aimed towards vital points of the body such as the eyes and throat.
To confuse matters even more Bassai Sho is written exactly the same way as a Chinese form known as baji xiao which has a counterpart form known as baji da (from the bajiquan style), so perhaps this kata pair and the Dai-Sho naming scheme originates from China, invalidating the claim Itosu authored most of the -sho kata.