Espeon and Umbreon - Yin and Yang Love
At the same time, two Pokemon are born. Two Eevees. And by fate, they are intertwined. Through being chased by enemies, the two meet, and become best friends. Soon, they become MORE than that. But when they are taken in by a kind trainer, they save an Eevee from the clutches of Team Rocket and both evolve into Umbreon...