The Keiyo Series is a saga made by Cuzco (ManaphyPhione (Banned)/SammyShinx/Cuzco) that focuses on three kids who realize that their family have turned into Pokémon, who then go missing. It is currently on hiatus, though the author has stated it will return.
See transcript to see the progress.
View it here. The Keiyo Series/Transcript#First Day