Pallet town I'm back

Ash and Serena used to be lovers before Serena moved away to kalos. This caused them to breakup and leave them both heartbroken. What happens when Serena moves back to Pallet Town and attends Pallet high? Will Ash and Serena reunite and start their relationship over again or will something or someone stand in their way.

Disclaimer: I do not own Pokémon or any of its characters.