Nomikai
Nomikai (飲み会, Nomikai</i ?) literally means "drinking gathering", and refers to the evenings that the Japanese to relax and have a good time. These evenings generally take place in Izakaya, a type of bar-restaurant.
If we talk about nomikai for a gathering of friends, the real social phenomenon is nomikai between co-workers. It is not uncommon to come across groups of salarymen, sometimes very drunk, in the Nihonbashi neighborhood.
It's always the boss who suggests going out to do nomikai, and it's impossible for the others to refuse.
A nomikai always begins with the famous "Kanpai!" (what is called a toast, in Spanish "Salud" or "Chin chin") and ends with a skilful calculation of division of the bill remembering that the youngest pay less, the older ones pay more and between the two the scale It is more or less linear.