Kanna no Kanna

Kamishiro Kanna was summoned to another world to be a hero; but the one who summoned him was a scheming princess and when his mana measurement showed 0, he was about to get rid of. Together with a half-elf kyonyuu silver haired bishoujo he met in the palace\'s prison they escaped riding a dragon she summoned.

The thing Kanna didn\'t know is 3 days after his escape from the palace, the princess did another summoning and summoned 3 high school students which happen to be his close friends.