The traditional Saké toast is "Kanpai!" This Japanese term literally translates as "empty or dry cup" though its basic meaning is "Let us drain our cups in friendship." It is equivalent to "cheers."
Saké is intended to be a social drink. There is a Japanese custom, called oshaku, that you are not supposed to fill your own cup of Saké. Someone else must pour it for you. This is considered to be a way for people to bond and make friends. Nowadays, this custom is not always followed and it is not considered a significant faux pas to ignore it. If someone is going to fill your glass for you, you are supposed to hold your glass rather than leave it on the table.
In Japan, a bottle of Saké is often given to commemorate special occasions, much like we would give someone a bottle of Champagne. I would certainly much prefer a bottle of Saké to Champagne any day.
Saké is ceremoniously drank on New Year's Day to celebrate the new year. I toasted this New Year with a bottle of Saké.
Saké is also used in numerous religious ceremonies in Japan. For example, in traditional Shinto wedding services, the bride and groom will share a glass of Saké.
There is even a new, special holiday for Saké. October 1st is Saké Day ("Nihonshu no Hi"). This holiday originated in 1978 by a declaration of the Japan Saké Brewers Association. Why was October 1 chosen? Interestingly, the Chinese character for Saké is very similar to the Chinese zodiac sign for the Rooster, the tenth sign. Thus, the first day of the tenth month, October, became Saké Day. It probably also helped that October generally is the start of the Saké brewing season.
I will be sure to remind everyone about Saké Day when it arrives this October.
If you visit True Saké, an all-Saké store in San Francisco, you may notice a green ball of vegetation hanging in the entrance way. This is a sugidama, also known as sakabayashi, which is a globe of tightly bound sugi ("Japanese cedar"). These green balls are traditionally hung in front of Saké breweries when the first batch of Saké is pressed each year. They also hang in front of Saké bars and stores. As the months pass, the needles of the sugi will turn brown. It is said that once they have turned brown, the Saké has aged enough to be ready for drinking.
The sugi tree holds special significance in the Shinto religion. The oldest Shinto shrine is said to be the Omiwa Jinja in Nara Prefecture, which houses Matsuo-sama, the primary god of Saké brewing. The sugi from the grounds of this shrine are traditionally used to create all of the sugidama.
Tanks for Saké brewing were once made of sugi wood as were the masu, small boxes used as cups. It was thought that sugi would prevent the Saké from spoiling.