It is speculated by some that the kata Naihanchi (Naifanchi, Naifanchin, Naihanchin) is derived from a Chinese Tam Tui (Northern Mantis) form called Dai-Po-Chin (Dai-Fan-Chie in Cantonese, and Da-Fan-Che in Mandarin). Some say this means "whirlwind" because of arm movements in it, while other say it means "Big Chariot." There is another similar form in some Mantis styles called Xiao-Fan-Che, or "Little Chariot." They are said to be part of the Chariot (Fan-Che) set from the Shaolin temple. Tradition has it that the "Dafanche" was part of sixteen sequences systemized by Shaolin Monks at the prime of Shaolin history, and that it was later perpetuated into the Northern Mantis style. If Naihanchi is not derived from it, it is at least similar to it. But the similarities in the name and in the form are a little hard to overlook.
One report of how the kata got to Okinawa is through the Chinese master Ason. The story goes that Ason was one of the first Chinese teachers in Kumemura, and built up his style on the base of the original Naihanchi Kata, which apparently he brought from China. His students were Sakiyama, Tomigusuku, Gushi, Nagahama and Tomoyose. But the style ended with Tomigusuku and was not passed on. The report alleges that only the Naihanchi kata was passed on into the Naha te, from where Matsumura and Itosu got it. Some believe that Matsumura was a pupil of Ason, but other reports claim that Ason came to Okinawa too early on for that to be true. Whatever the case, somehow the kata got from Ason to Matsumura, directly, or through other masters. Then again, did Matsumura get it from China, directly from Shaolin? It is not out of the question to suppose that this kata was perpetuated in Shaolin as well as the Mantis style.
Some report that Hohan Soken once said that Naihanchi was the name of a master that brought the original kata to Okinawa, and that he was perhaps a Chinese master. Could this man be the same as Ason? Could Ason have had Naihanchi for a nickname or something?
Some claim that Bushi Matsumura created both Naihanchi Shodan and Nidan, apparently from a pre-existing kata, perhaps the one he recieved through the Naha-te line if that story is true. Some believe either Itosu or Choki Motobu created Naihanchi Sandan. Some say that Itosu created all three of them, and that Matsumura had nothing to do with the first two at all. However, Nabi Matsumura taught Naihanchi Shodan and Nidan, but he never studied under Itosu.
From the claim that Naihanchi came through Naha-te developed the theory that the kata was originally called Naha-chi or Naha-chin, from the place-name Naha.
Another theory for the origin of the word is that the original form of the word was the Chinese word Nai-fan-chi. In Chinese, the particle 'Nai' means "inner" or "inside" and probably refers to pointing the toes inward. 'Fan' means a clawed foot of a certain animal. 'Chi' means the soil or foundation. So the original name, according to this theory, probably meant something to the effect of being rooted to the ground in correct stance.
Another claim is that the character for the word "chin" or "chi" points to the chinese system of "Chin-na" (Qinna) and refers to the techniques of gripping vital points (Tuite).
And still another theory is that Chi or Chin could mean "battle" as it does in the word Sanchin. The word 'Naihan' could refer to the narrow paths through rice fields that resemble squares. Therefore, it could mean "battle in a ricefield." Or if we go back to the possibility that Naihan or Naiha is another form of the word Naha, we get the meaning of "Naha battle."
In light of the existence of the apparent ancestral kata in the Chinese Tam Tui system, all of these other theories on the origin of the name are doubtful, and it is much more than likely that the name originated phonetically from the Chinese Daifanchi.
Funakoshi called Naihanchi by the name Tekki, meaning "Iron Horse", which refers to the stance used in it. "Iron" refers to its strength and stability. "Horse" refers to the fact that it resembles a man riding a horse.