Re: Irimi or Omote?!!!
in ki-aikido style, there is terminology like "irimi ura" such as "irimi tobikomi" which translates as I understand it to roughly "enter step behind"
like Jun says, its best not to consider "irimi/tenkan" equivalent to "omote/ura".
for a swordsman, use of front/behind can be problematic since omote/ura are used to denote sides of the blade