True story on what??
Hello.
I am unsure of the question but will try to put across a possible answer to the question I think you asked.
"Was Iaido used indoors, or when greeting a person as part of a 'pre-emptive' attack?"
Basically, NO. Iaido is a system that was devised to be used on the battlefield or in the street, but on FOOT no seated in 'Seiza'.
Although many schools included 'Seated waza' the techniques were never intended to be used indoors.
During the Edo period Samurai were required to leave their long swords (Katana) at the door or with a servant as a sign of respect to the host. Short blades were permitted to be worn and several ryu have Iai techniques for use with the 'Wakizashi' or 'Tanto' (Takenouchi ryu is one of these).
Indoors, Samurai would not have used the Iaido techniques as the possibility would never have arisen.
There is much debate about this but exactly why the Iaido Seitai gata were formed using the seiza sitting posture is still not really certain..What is certain is that (modern) Iaido was never intended to be used by an assassin or by a soldier/bushi. It is generally accepted that the modern forms allow the development of spirit, techniques and accuracy that can 'help' the trainee and society at large in creating a 'decent-focussed individual'.
'Iai' as a term consists of two Kanji, the first 'I' means 'to be present, exist', the second 'Ai' meaning 'to match, fit, agree with, be correct'. The term Iai is a complex one to understand but one that does not mean 'seated facing'. (Although it would be good to hear Iai practitioners on their beliefs on the terms meaning..)
Basically the story above is not correct, and fails to grasp the meaning of Iaido/Iaijutsu in its entirety. (Like I have!!)
Complex. But not what is written above.
Abayo.
Ben Sharples.
智は知恵、仁は思いやり、勇は勇気と説いています。