We call a year-end party "Bonenkai" which means a party being held to help people forget the troubles of the past year. We often celebrate year-end parties with our co-workers, friends, neighbors and etc. I had mine with my college friends yesterday in Osaka where in a lot of people spend their year-ends. We actually talked about our businesses, families, other common friends. We have been doing it for more than 20 years and the main topic is gradually changing from our marriages to our businesses, children and aging parents.