anyone growing or has korean sweet potato

[amtun13892]

I just came back from japan and south korea and had a chance to try street food and I fall in love with just one - sweet potato. I started looking for one here in southern ca, like H mart or japanese supermarket which sell different japanese sweet potato. none of them are comparable to what I ate there in Seoul. the one that tried there are sweeter, juicier, creamer and inside color is light yellow. OMG!! I posted some pic . I guess it is called gun-Goguma or pumpkin sweet potato, something like that.
if there is anyone here grow the type that I am looking for or where to get those , please direct me. my goal is to grow here so that I can have year around.
aung