Shunsuke Yamane

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.

Avid bookworm and college student Motosu Urano ends up dying in an unforeseen accident. This came right after the news that she would finally be able to work as a librarian as she had always dreamed of. When she regained consciousness, she was reborn as Main, the daughter of a poor soldier. She was in the town of Ehrenfest, which had a harsh class system. But as long as she had books, she didn't really need anything else. However, books were scarce and belonged only to the nobles. But that doesn't stop her, so she makes a decision... "If there aren't any books, I'll just create some."