Simply go to Help & Options on the main menu and then press all four trigger and shoulder buttons (cn_LB+cn_RB+cn_LT+cn_RT) then go to movies and navigate to the losing poses section. Watch any ones you want till the achievement pops.
If you're playing the trial it's possible to get it with just the free characters given. (Ayane, Kasumi, Hayate and Ryu plus whatever two are in rotation.)
Go to fight, versus and then fight settings.
Set com level to 8, max health to smallest, then solo rounds to 1 then hit cn_B to save.
Now go to solo match, confirm controller side.
Select any character then select another character, pick stage and let the CPU beat you.
Now select change character, pick a different first character. Rinse and repeat for all the free ones. (If you own the full game, just keep repeating with any of the characters till the achievement pops up.)
(You should have six losing poses already but in case they don't update or they remove the two rotating free ones, I've posted four other ones you can get; Lei Fang, Jann Lee, Ein nd Hitomi in that respective order for the lessons listed below.)
Next go to training and then tutorial.
Select "24. Character-specific holds (Level: Advanced)" then go to the bottom to "Mission 24.1: Character-specific holds" and let the CPU beat you.
Go back to tutorial menu and pick "27. Attacks that get through guards (Level: Advanced)" then go to the bottom to "Mission 27.1: Unblockable attacks" and let CPU win again.
Go back a third time to now select "40. Tag matches (Category: Tag)" then "Mission 40.1: Tag combos", hit cn_RB to tag in Ein and then let CPU win.
Going back to tutorial menu for the final time go all the way to the bottom for "42. FINAL TEST", start the mission and lose.
Now return to the main menu.
Select extras and then movies.
Press cn_RB twice and watch both videos. (Jann Lee and Lei Fang)
Press down on this screen till a new screen comes up and watch two more. (Hitomi and Ein)
Credit to Exe the Hero for the tutorial mode tip.