Ryuu Lion is a prominent character in the anime series 'Dungeon ni Deai o Motomeru no wa Machigatteiru Darou ka', often referred to as 'DanMachi'. She is an elf and a former adventurer who now works as a waitress at the Hostess of Fertility tavern. Known for her calm demeanor and exceptional combat skills, Ryuu has a mysterious past that gradually unfolds as the series progresses. Her interactions with the main protagonist, Bell Cranel, are significant, as she occasionally aids him in his adventures in the dangerous dungeons of Orario.