Great video. More prominently the affinity to beer can be attributed majorly to its historical significance. Dating even before Sengoku period, when local warlords in Japan used to hold big parties during special occasions, before a big war, etc. The warlords used to drink alcohol, mostly made from rice with his subordinates. These warlords were called Bushi, who were later called Samurai. They used to have massive parties with drinking and eating through out the day. This was a major influence on modern Japanese drinking culture, this is a major aspect for the creation on modern Nomikai where colleagues go for a drink after work to improve teamwork and mutual bond.