Mori-senpai Has an Apprentice Candidate! - S1.E22

When the son of a gangster, Ritsu Kasanoda, seeks Mori for tips on how to change his scary image and gain friends, the Host Club immediately jumps at the opportunity to change his image, making many humorous results of their efforts. The members of the Host Club also frequently call him Casanova and bossa nova. However, Ritsu ends up discovering Haruhi's secret.