The Irregular at Magic High School, Vol. 16 (light novel)

Every year the Yotsuba Clan gathers it's most influential and powerful members. And like always, Miyuki has gotten an invitation. There's only one big difference this time: direct orders from the Yotsuba matriarch requesting her presence on New Year's Day and a bargain that may repeal Tatsuya's status as a pariah if Miyuki is willing to do whatever it takes...