Due to being an island country surrounded by the sea , and isolated , contact with other races was restricted to some extent , and in addition to the above characteristics , the way for generating a unique and rich culture was paved . また、周囲を海に囲まれ個立した島国であることで、他民族との接触に一定の制御が加えられ、前記の特質に加えてさらに、独特の豊穣な文化を醸し出す下地ともなってきた。