[1] Bōnenkai are observed by parties of friends or co-workers or sponsored by a company or business office for their employees.
[4] Bōnenkai are seen as times for bureikō (無礼講) or letting one's hair down and not worrying about the boss/employee formal relationship or the rank and age divisions.
[6] These types of parties did not become commonplace in the regular populace of Japan until the abolishment of the feudal ruling system in the late 19th century.
Around the same time period, a story written by Japanese author Tsubouchi Shōyō entitled 忘年会 was published in a newspaper.
[6][7] In post-occupation Japan, the "lifetime employment systems" established by some companies incorporated many company-organized events, one usually being an end-of-the-year Bōnenkai in December.