S01E06 — The Grade School Host is the Naughty Type!

An elementary school brat, Shiro Takaoji, seeks help from the Host Club's King to win the heart of women, but what he doesn't say makes all the difference in how much help he gets. He attempts to run away, calling Tamaki a "fake king", and Tamaki and the others infiltrate the elementary school, discovering that Shiro has a crush on a girl who would soon be moving away. Tamaki explains to him he didn't wish to please women, but only to please one woman - the girl he has a crush on. He had joined the Classical Music Club to make her happy and play the piano with her. Shiro learns his part of the piano duet he was supposed to have played with her, and the host club ends up allowing him and the girl to have a small concert in the host club lounge. The episode ends with Shiro entertaining at the host club, warning the clients not to tell his girlfriend; she'll get jealous if she hears he's hanging out with such beautiful women.