Riolu first appeared in DP071, where it was being "rescued" from a research facility and then escaping from its "rescuers". It later encountered Ash and his friends in the forest.
Due to being targeted by groups of people intending to use it for their own malicious purposes, Riolu had a difficult time trusting those outside its kingdom, including that of Ash and the gang. However, upon learning that Ash could understand its aura, Riolu started forming a bond with the trainer as he claims it can trust him. During the time of being in Hunter J's custody, Riolu used its aura to communicate with Ash to let him and the others know where it was. Brock states that Ash was able to sense where Riolu was due to how strong the bond between him and Riolu was.
|Aura Sphere||fighting||DP071: Pokémon Ranger and the Kidnapped Riolu! Part 1|
- This Riolu acts as a reference to the Aura Sphere Riolu in Pokémon Ranger: Shadows of Almia.