The reason for Ienari's numerous offspring can be traced back to his ascent to Shogun at age 15, at which time he was instructed by the Hitotsubashi family to father enough children to dominate the nation with the family's bloodline.
非常に多くの子を作ったのは15歳で将軍職を継ぐ際に、子女を多く儲けるように実家・一橋家より訓戒をうけたためであり、徳川家の天下を一橋家の系統で押さえるためでもあった。