> You move into a new region after your mom passes away, so you go live with your dad
> He's not a bad person, but he is kind of a screw up
> The day he's supposed to pick you up at the pier, he completely forgets
> It gets late, you decide to try and go home by yourself, together with your eevee (that actually used to be your mom's)
> Get intercepted by some thugs (not an evil team, just regular burglars)
> They battle your level 5 eevee, but have like, level 30 Weezing etc.
> You obviously lose
> They take your Pokémon
> Only then your father appears
> "I'm so sorry, I totally forgot!" etc.
> He works as a delivery man for the regions professor
> You tell him what happened, he tells you not to look into it, since criminals in that region were violent and dangerous
> Eventually you get tired of his shit, steal one pokédex and one of the professor's three rare Pokémon (region's starters) and go on to find your pokémon
> Your rival is one of the professor's assistants who have a real strict sense of justice(think of a tsundere girl)
> Your dad picks the last starter and tries to convince you to come back
> They don't let you compete in Gyms for the first part of the game because you lack an official trainer card
> Evil team wants to test the boundaries of Pokémon evolution (region's legendary is the entity that enables evolution in Pokémon)
> They conduct experiments on the Pokémon they rob
> When you eventually find your Eevee, it is mutated in a state that can change between all of his evolutions during battle (it's the last battle against evil team master)
> Once you beat evil team, you get your trainer card and are able to fight the gyms (it's the post game)