There are 12 Trophies that can be collected.

Bronze

(Best friends forever!)
Clear Arcade mode using Xiaoyu and Alisa together.

That was quite a fall.
Use Xiaoyu and land 5 Storming Flower counter-hits.

Please accept my feelings.
Use Alisa and land 5 Spam Bomb attacks.

Meet your maker!
Use Devil Jin or Kazuya and land 5 beam attacks.

I always like a good fight.
Fight 10 times against human opponents.

That was a nice combo.
Land 10 Tag Throws.

Just like in the movies!
Perform a Balcony Break.

Silver

I'm unbeatable!
Win 1 round without taking any damage.

I'll smash you to pieces!
Land 5 Tag Assaults.

Stay down!
Land 10 Tag Combos.

Are you even trying?
Escape 5 Tag Throws.

Gold

See you in the movie.
View all ending images.

http://www.ps3trophies.com/forums/ps3-trophy-news/6376-tekken-tag-tournament-2-prologue-trophy-list.html