After the Kamakura bakufu (Japanese feudal government headed by a shogun) was established by MINAMOTO no Yoritomo, oban was served at important ceremonies such as Genpuku (coming of age) and Ito (moving), and the 'Saishu no oban' that was served in the beginning of the year became one of the most important ceremonies of the buke (military) government.
源頼朝による鎌倉幕府の成立以後、元服や移徙などの重要な儀礼の際には椀飯が行われ、とりわけ年始に行われる「歳首の椀飯」は武家政権の最も重要な儀式の1つとして行われるようになった。