Shuhei Yamamoto

The anime centers around a boy named Kouta Kouka (Kouka Kouta in Japanese name order, an apparent wordplay on Coca-Cola). Kouta strives to be the world's best Bottle King at the Bottle Battles in the virtual Drink World. He comes across his Bottleman partner Colamaru and then wages battles with various rivals.

Osono and Eisuke would like to get married but with her up to her neck in debt due to her late father's illness and him trying to raise the funds to start a business, they can't afford to do so. Osono agrees to work as a geisha and eventually is tricked into becoming a businessman's mistress, all because she wants to help her lover. The businessman, in turn, is actually only interested in training her so he can hand her over to a palace official in exchange for a trade agreement...