Shelby was Strat's childhood girlfriend. They had gone on many fun adventures together, but during adolence, Strat's behavior became angrier and more erratic. This was way too much for Shelby, so she made the decision to break up and cut all ties with the yoshi she once loved. Strat was heartbroken, but realized how much he had hurt her. He needed to take some time for self-reflection, and doing so, decided it'd be best if he left her alone forever.

But that was then. Perhaps a reconciliation is in order?