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year-end party; "forget-the-year" party; bōnenkai
今年の忘年会の幹事になった。
I became the organizer of this year's year-end party.
忘年会で上司と思い切り乾杯できた。
I got to toast freely with my boss at the year-end party.
忘年会の出席者が集まり賑やかな宴が始まった。
The year-end party attendees gathered and the lively banquet began.