Based on the provided information, Shikibu-taifu Yasumasa Sakakibara appears in the anime "Shinshaku Sengoku Eiyū Densetsu - Sanada Jū Yūshi The Animation" and its specials, voiced by Wakamoto Norio. The historical Sakakibara Yasumasa was a prominent Tokugawa retainer, distinguished for his service as one of the "Four Guardian Kings" of the Tokugawa clan. His military record includes participation in significant battles such as Anegawa and Komaki Nagakute. He later governed the Tatebayashi Domain until his death in 1606. While the anime focuses on the Sanada clan's conflict with Tokugawa Hidetada at Ueda Castle and the Battle of Sekigahara, the available sources do not detail Yasumasa Sakakibara's specific actions, dialogue, character traits, narrative arc, or development within the anime's storyline.