The Quintessential Quintuplets

Fuutarou Uesugi is the smartest student in his school's poorest household. The single condition his new private-tutor contract attaches to its inflated paycheque: he has to keep his five students from flunking out. The five turn out to be the Nakano quintuplets, all in his class, all roughly equally hostile to his lesson plan. The series alternates between Fuutarou's slow conversion of each sister into something resembling a willing student and the framing device that opens every episode — an adult Fuutarou about to marry one of them, with the show withholding which until the very end.