The Host Club is a group of attractive high-school boys who, along with their "secret princess" Haruhi Fujioka, entertains guests after school. There is no fee for their service. The funds are generated through mixers, events, albums, and sales of Host-owned items.
Ouran High School's Host Club was founded by Tamaki Suou, along with his best friend, Kyouya Ootori, while they are 3rd-year students at Ouran's Middle School. Having come to Japan to live with his father while his mother remained in France, Tamaki envisions a club where he can once again feel the bonds of "family," as well as provide guests a place to enjoy his "world of beauty." Kyouya goes along with the idea as a way to expand his narrow view of the world and his place within his high-powered family. Next conscripted are Mitsukuni Haninozuka, who wishes only to freely enjoy cute things and sweets, as well as his cousin and companion Takashi Morinozuka, both of whom are ahead of Tamaki and Kyouya by a year. Finally, Tamaki enlists Kaoru and Hikaru Hitachiin, identical twins who are a year younger and impressed by Tamaki's determination and acceptance of their similar yet differing natures. The club actually begins operation when Tamaki is a 1st-year in high school and is an immediate hit with the school's girls. The final addition to the Host Club is Haruhi Fujioka, a female scholarship student who becomes the club's errand boy after accidentally smashing an $80,000 vase intended to raise funds for the club. Her androgynous appearance and demeanor fools the boys for a brief while, up to and including the time that she is promoted to official Host; but once her gender is revealed she is made to keep it a secret, causing a great deal of havoc for everyone involved.
Visiting guests (99% of whom are girls) typically designate a favorite host who chats with them, flirts with them and has afternoon refreshments with them. Once in a while, a customer "host hops" or, occasionally, one host will take over for another. The customers do not "buy" the attentions of their chosen host, but use points earned by purchasing host-related merchandise and tickets for host-sponsored events like dances, garden parties, etc. The club frequently cosplays and has themed days during which time the salon is decorated to suit the theme and the hosts wear costumes.
While many of the anime episodes and manga chapters reflect Host Club official activities, the personal lives and relationships between the Hosts often serve as equally well-explored plot points, expanding the storyline and deepening characterization.
While not all of the members have an official role in the club, all have a designated role in Tamaki's fantasy "family."