The Hidden Dungeon Only I Can Enter

Emma invites Noir to a party for nobles. Meanwhile, as a baronet, Noir's father is unfairly prohibited from renting a space for Noir's shop. At the party, the Earl announces the notorious Phantom Thief has threatened to steal his jewel, the Mermaid's Tear, so he has hired the Lahmu guild as security. Emma is approached by Mike Kental, a noble, who challenges Noir to see who the better dancer is. Noir uses LP to gain dancing skills and is declared victor. The Phantom Thief then arrives, steals the Tear, and kidnaps Emma. Leila Overlock, from Lahmu, chases her with Noir. The Phantom Thief summons a Phoenix, which Leila defeats while Noir defeats the Phantom Thief. Suddenly, they are pinned by her partner, Tom Bertholda, who declares he will marry Emma. A furious Noir declares Emma is precious to him. Emma awakens and they defeat Tom together. Afterwards, Emma is worried that Noir might think she is now dirty, but he reassures her with a kiss. Despite being from rival guilds, Leila agrees she and Noir can be friends. As thanks, the Earl helps Noir open his shop and gets him a massive discount on the rent. (Source: Wikipedia)