There are basically two sets of blood vessels in our legs, the leg arteries and the leg veins. The functional difference between the two is the leg arteries carry blood from the heart down into the legs, and to the feet and toes.
The name Ken is a baby boy name. The name Ken is a Welsh baby name. In Welsh the meaning of the name Ken is: Clear water. The name Ken is an American baby name. In American the meaning of the name Ken is: Clear water.
In the story, since both main characters have the same first name, to differentiate one Nana to the other, Nana Osaki affectionately called Nana Komatsu Hachi, because she thinks Nana Komatsu behaves like a dog, faithful but sometimes annoying. This is actually a play of word. The female name Nana is a homonym of the Japanese word nana that means seven, and while Hachi is a common dog name in Japan, it is also a homonym of the word hachi that means eight.