Its 300 years in the past, in the Hisui era, your the protagonist that got transported in here, when you are exploring after all you passed throught (in the history of Legends Arceus), when you get to the Forest nearby, a prencese is felt, a 9 ft girl with a furry and Ghostly appearence, it looks like a Snealser but fused with another Pokémon, She looks at you and seems happy

Finally! I found a Boy that dosen't get scared of me~! Giggles