Lost Kat is a miscellaneous PlayStation unlocked trophy in Gravity Rush.
How to unlock[]
This trophy unlocks when the player, as Kat, takes their first steps the second they have control over her. This will come after a short intro/credits sequence preceded by a prompt to break the apple free from a tree by simply either tapping it, or the DualShock 4 touch pad depending on the version one is playing.
Just tilt the left stick forward to unlock the trophy, simple as that!
Additional Information[]
This is a bronze trophy; as it is listed above all of the other trophies in the game (except for "It's All Relative"), and being unlocked by just moving forward, it is the very first one players will unlock, it's unsurprisingly the most common trophy unlocked, and is impossible to miss.