【The book version is now available from Famitsu Bunko and selling well!】

Kaji Yusaki, playing on a smartphone app, is suddenly sucked into his device and transported to a game world.

There, a dragon claiming to be a god tells him, "I'll give you territory and a castle, so become a king and create the strongest army." Yusaki, bewildered and made the lord of a dilapidated castle, finds himself at a complete loss.

When he performs the only thing the god taught him—warrior summoning (gacha)—the one who appears is Orion, a girl of R (Rare) rarity.

Orion, who has an inferiority complex about her low rarity, and the unreliable king work together to rebuild their dilapidated castle and create the continent's strongest army.

They sometimes sweat through part-time jobs, sometimes get chased by goblins, sometimes perform gacha pulls, and sometimes struggle to repel the kings of major powers.

Also cross-posted on Kakuyomu.