This Riolu, nicknamed Tokyo, is not a basic Riolu. This Riolu was seen to be a big fan of THIS, and has grew fondness over the days.
Tokyo's Egg was left by three other Trainers before it was able to be released into the North Lake Miloch and hatch here. There was no Trainer which was able to care for him and become their unofficial Pokémon. The Emanation Pokémon would stay in its new home for a long time.
Like Ash's Froakie's egg, Tokyo's egg had an unique early life. Despite being passed from hand to hand, it was taking an abnormally long time to hatch. This was because three other Pokémon Trainers were able to take care for it every day and got passed by other Trainers, before the last one was able to release the egg back to North Lake Miloch. When in North Lake Miloch, the egg was able to successfully hatch into a Riolu.
As a wild Riolu[]
The wild Riolu, which was nicknamed Tokyo, decides to start living at North Lake Miloch, and wait if there was a Pokémon Trainer which was able to care for him and become their unofficial Pokémon.
In Pokémon Galarian Team[]
To see more about Tokyo in Pokémon Galarian Team, see here
Tokyo also appears in User:Kaaaylee2007's fanfiction Pokémon Galarian Team. He likes Treecko and Aceburn a lot, and cares about each member of the Team. His parent is a female Lucario.
Both of them were kept by multiple Trainers. Tokyo's egg was kept by three unknown Trainers before being hatched, while Larvitar was kept by Ash Ketchum.
Both of them are first stage members of their evolution lines.