Koshi is a coastal region,based off off of Kyushu Island in japan (Here:http://en.m.wikipedia.org/wiki/Kyūshū).The region itself sits in the oceans southwest of Kanto.As far as the land itself,it is similar to that of a Tropical forest Biome,and there are many dirt paths and forests all across the region.
All cities and towns in the Koshi region are primarily named after flowers,as a sort of nod to the variety of plant life on Koshi,and the surrounding smaller islands.The islands surrounding it are known as the Shikoku islands.
The professor of the region is named Allen Hawthorn,based off of the Hawthorn tree. He has short Blonde hair, light green eyes, and a small goatee. He wears a plain gray shirt under a white lab coat, grey Khaki pants, and black loafers.
There are,as in every other region,three starter pokemon to choose from for beginning trainers.In the Koshi region,the starter pokemon are Slothel, Empup, and Calflow.