Arezu is a warden tasked with watching over the noble Lilligant, Lady of the Ridge, in the Crimson Mirelands of Hisui. She is a member of the Diamond Clan. Her dialogue sometimes contains hair puns such as "oh snip" or "cutting edge." Other times, Arezu speaks excitedly, using slang and other forms of shortening or calling the player nicknames.

The sixth Gym Leader Galar Trainers face in their Gym Challenge in Pokémon Shield. She has been the Gym Leader of Circhester since her twenties. She is also the only known Gym Leader to have ever defeated Raihan, who is said to be the strongest Gym Leader in the Galar League. At one point, she wanted her son Gordie to run the Gym as her successor. However, her son wanted to be a Rock-type user instead. This led to a battle that caused the whole town to split, with the two never speaking to each other again. Despite this, Melony somehow became the first member of Gordie's fan club. While normally generous and bighearted, she loves to battle hard, along with hitting the opponent's weak spot with unflinching accuracy. Her battle style is described as severe and stoic. It is believed her harsh battle style was influenced by the fight she had with her son. Melony's Gym is considered a major roadblock by many challengers who visit, the reason being the powerful Gym Trainers strict coaching.