What feature of japan's geography allow it to develop its own distinct culture?

I believe the answer is: its distance from the mainland of Korea and China

Japan was surrounded by sea that separated it from Korea And China. This made it really hard for other Asian culture to come in and assimilate with Japanese's culture. As a result, japan develop a culture that is considered unique even if compared to other countries in East Asian region.

the committees of correspondence were the american colonies’ means for maintaining communication lines in the years before the revolutionary war. in 1764, boston formed the earliest committee of correspondence to encourage opposition to britain’s stiffening of customs enforcement and prohibition of american paper money. the following year, new york formed a similar committee to keep the other colonies notified of its actions in resisting the stamp act. in 1773, the virginia house of burgesses proposed that each colonial legislature appoint a committee for intercolonial correspondence. the exchanges that followed built solidarity during the turbulent times and bring about the formation of the first continental congress in 1774.