What is Ten-chi? Is it a martial art?
sorta...
Ten chi...
Well. *puts on professor glasses*
'Ten chi' in Japanese means Heaven and Earth.
It's derived from Chinese 'Tian Di', also meaning Heaven and Earth. Literally they both mean 'Sky and Ground/Earth'.
Tenchi is also a common name for swords back in ancient Japan.
Tenchi is also the name of the main character from the anime, Tenchi Muyo (No need for Tenchi/Useless Tenchi).
Also phonetically, it sounds like 'weather' in Chinese. 'Tian Chi' - 'Ten Chi'
Welcome to the board.
Tenchi here is a 90s harem anime, one of the earliest and most defining of the genre, with very strongly defined women - and their fans makes the backbone of the fandom.
(http://i.imgur.com/KgsiPl.jpg)