Mere days before he was to be crowned Prince of Pocketville, James vanished while on a picnic with his family. According to rumors, he wandered away when his parents weren't looking and got lost.
His parents spent all of their time and resources trying to find him, but after a year, he was presumed dead, and Ava was crowned Princess of Pocketville instead.
A few years later, James returned home with no memory of who he was, though he recognized Ava and Eva (but as old friends, not his sisters).
He constantly flirts with Eve, but instead of falling head-over-paws, she likes him less and less.
Eventually, James loses interest in Eve and starts dating Lili.