The Koremune clan was a family that produced good scholars of law; his grand-grandfather was KOREMUNE no Naomoto, who edited "Ritsu-no-shuge" (a written document on the criminal code) and "Ryo-no-shuge" (a written document on the civil code), and his grandfather was KOREMUNE no Kinkata, who compiled "Honcho Gatsuryo" (also known as Honcho Gatsuryo, a book about the knowledge of court rules, ceremony, documents in the mid Heian period).
惟宗氏は代々明法家の名門で、彼の曽祖父は、『律集解』『令集解』を編んだ惟宗直本、祖父は『本朝月令』を編纂した惟宗公方。