Who more closely related to Koreans: Chinese or Japanese?

Here is map here is a korea, china and japan. Do you think Koreans more closely related to Chinese or Japanese? Here is the hint: Ethnic Chinese costume, Korean, and Japanese... Not clear yet? A population genetic study was undertaken to investigate the origin of Koreans. Genetic distance analyses by both cluster and principal components models were performed between Koreans and eight other populations on the basis of 47 alleles controlled by 15 polymorphic loci. These analyses demonstrated genetic evidence of the origin of Koreans from the central Asian Mongolians. Further, the Koreans are more closely related to the Japanese and quite distant from the Chinese. The above evidence of the origin of Koreans fits well with the ethnohistoric account of the origin of Koreans and the Korean language.