Thunderstone

A Pokemon Mystery dungeon story where an Eevee who wakes up and finds herself transformed into a pokemon. She meets a Pichu as she wakes up, but little did she know, she would go on mysterious adventures with him to be a rescue team.

The pichu had a difficulty evolving due to his lack of happiness throughout his life, so he gave his only thunderstone to the Eevee, who he had quickly grew feelings for throughout their journey. But things didn't turn out the way the Pichu planned.