Yūken Ōyanagi (凹柳 夕剣 Ouyanagi Yuuken Literally meaning; Evening Sword, Hollow Willow) is the current lieutenant of the Second Division in the Gotei 13 under Shiroi Yoake. Additionally; he is the Corps Commander (軍団長, gundanchō) of the Patrol Corps and fulfills his job splendidly. As the current heir of the lower-noble house, the Ōyanagi Clan, Yūken is burdened with much responsibility from his duties. Appearing as apathetic and uncaring to the surrounding world, he is known by the Gotei 13 as, Yonagi (夜凪 Evening Calm).