Hetare Shoukanshi no Fuhoni na Shoukan

Rubin, a seemingly useless summoner whose conjuring attempts are comically futile, secretly dreams of defeating a dragon. Fate has a sense of humor when Rubin summons a mysterious prince who coerces him into going to an abandoned castle… where a dragon lives! Can a useless conjurer face the challenge of confronting a legendary beast? (Source: Renta!)