Iwai Seijo ni Naremasen Deshita. Kono Mama Stealth Shitai no Desu ga, Akuyaku-gao to Seirei ni Aisare Taishitsu no Sei de Yappari Iroiro Okorimasu

Despite being a kind-hearted young lady, Adite is constantly misunderstood because of her “villainous-looking” face, even failing the final selection to become a Saint. In truth, she does possess the power of a Saint, but she hides it, intending to live a quiet life with Sylvest, a fluffy spirit. However—an unexpected situation suddenly arises! What will become of this overly kind would-be Saint!? Source: MU