Brother: Let's play cards! Become the king of card games!
Sister: Play cards! Play cards! You don't know anything except playing cards, right?
Brother: Then I won't play cards, I'll just play tricks!
Sister: Bastard!
Brand new cards, brand new world, brand new summoning method!
In a world where there is only playing cards, people play cards besides eating and sleeping.
How can we live without playing cards?
