3000-nen Fuuin Sareshi Jaryuu-chan to Tomodachi ni Narimashita

Yuuto Kuroma, a 14-year-old with a serious case of chuunibyou, accidentally summons the ultimate Dragon King using a magic circle he had doodled purely on a whim… (Wait, seriously?)

On top of that, due to certain circumstances, Yuuto ends up becoming friends with a lonely evil dragon girl who had been sealed away for 3000 years…!

(Source: Ichijinsha, translated)