In addition, in 1553 Yoshimoto revised the Imagawa Kana Mokuroku (the Imagawa clan's basic house law to control the territory), enacted by his deceased father Ujichika, and expanded on it by adding articles collectively referred to as the Kana Mokuroku Tsuika (Expanding on the house rules left by Ujichika), in which he declared abolition within his territory of shugoshi funyu chi (the bakufu-owned area within a feudal lord's territory where access was restricted even for the feudal lord authorized as shugo) instituted by the Muromachi bakufu (Japanese feudal government headed by a shogun), and definitively cut off relations between the Imagawa clan as a Shugo daimyo and the Muromachi bakufu, even though this relationship had barely persisted until then.
更に天文22年（1553年）には亡父の定めた今川仮名目録に仮名目録追加を加えたが、ここにおいて室町幕府が定めた守護使不入地の廃止を宣言、守護大名としての今川氏と室町幕府間に残された関係を完全に断ち切った。