They ate people to survive
The original inhabitants of Japan are known as the Jomon culture. This cultural period is dated by pottery to have started sometime around the 14th century BCE. Subsistence was derived from fishing, hunting, and light agriculture and they clearly had a complex culture for the period based on the intricate artifacts found. Around 1000 BCE, an infusion of culture and technology that spread gradually west across the islands of modern Japan from mainland East Asia likely along with a population known today as the Yaoyi people. It was this new population or more likely a blend between the Jomon and Yaoyi peoples who were the ancestors of the modern Japanese population.
For much of the early history of the Japanese Empire (600-1200 CE), there were references to a population known by them as the "Emishi" on the frontier in northern Honshu. Though it is unclear exactly who they were, it is safe to assume based on Japanese and non-Japanese historical records that the Emishi were a post-Jomon culture that were related to those original peoples of Japan. For example, it is clear that they did not speak Japanese and that they resisted the expansion of Imperial control into the region, fighting several wars.
Hokkaido, the northernmost main island plays host to what is most likely the modern decedents of both of these groups, the Ainu. Only recently recognized as a distinct indigenous group from the Japanese ethnicity by the Japanese government, they have historically suffered harsh cultural and physical oppression ever since Japan began moving a significant presence into Aniu-populated areas. They are still frequently discriminated against by Japanese people despite the official government position so it is suspected many Ainu, most of whom are not 'pure Ainu' so to speak, do not claim their ancestry. While official numbers stand at around 24-25,000 it is believe that there are about 200,000 people with significant Ainu ancestry on Hokkaido, the Sakhalin Islands, and the Kuril Islands. Note that some of this territory is occupied by Russia.
Modern day Japan is experiencing an economic downturn since Akihito, succeeded the throne from his father. Credit is very hard to get in Modern day Japan and living frugally has been emphasized.
The large red disc represents the rising sun. The Sun
1500bc References to the consumption of whale meat date back to Kojiki, the oldest surviving book in Japan, written in the eighth century.