Today, my father went to a bachelor party. I think this is unfamiliar to Japanese people since they don't have this kind of custom. Well, a bachelor party is a stag party held for a bachelor, usually on the night before he is married.
The history of bachelor party is thought to have originated with a bachelor dinner that was traditional in ancient Sparta in around 5th century BC, where soldiers would toast each other on the eve of a friend’s wedding.
The task of organizing a bachelor party is often traditionally assigned to a male sibling of the bachelor or to the best man. Otherwise, any close and/or reputedly party-minded male friend will organize it. The planned activities of a bachelor party are traditionally kept secret from the groom.
There is a similar party to be held for the bride-to-be which is known as a bachelorette party. Also, there is a version so-called Stag and Doe party, in which both the bride and groom attend.
The countries that have this custom are Australia, Austria, Canada, Denmark, Germany, France, India, Italy, Russia, Spain, U.K. , and the U.S. I wonder why Japan doesn't have this kind of party.