Dragon Ball: Raging Blast

Once you get all characters, this achievement is easy to unlock, although it will take some minutes. I´ll tell you the faster way to unlock this:

First, enter the museum with normal Gokuh. You´ll see two options: Introduction and History. Press A to enter Introduction. From here, you´ll be pressing RB until you get into normal Gokuh again. Press B and then LB, and then down. You should see the word "Introduction" in blue in Broly SS3.

Now, enter into History in normal Gokuh. Press A on any bubble, then B, and keep selecting the other bubbles. You must press A on all of them. Once you´ve done this, press RB to change the character and repeat.

Once you see all Introductions and History bubbles, the achievement will unlock right away. If you´ve seen all of them and you still haven´t got it, just go back to the screen where it says "Introduction" and "History", and search which one of which character isn´t on blue. That´s the one you have left.

If you have all of them in blue, you don´t have all characters. Keep in mind that you should fill all spaces in the character screen, and have Vegeta SS3 and Broly SS3 in there too.