Kamen Hakushaku wa Kurosuishou no Hanayome ni Koi wo Suru

Christa is offered in an arranged marriage to Gerald, a man with a reputation as a misanthrope who always wears a mask. Gerald coldly tells her that he wants an heir, not a wife, and that "you drive me crazy." But he is gradually moved by Christa's kindness and he begins to open up to her. Just as their hearts begin to connect, an unexpected situation arises regarding Gerald's secret!

(Source: Fairy Kiss, translated)