Looking up the origin of pun, I came across this for the origin of Japan. I suspect jih pun must be Cantonese. Tang Ho, as resident Cantonese expert, is that so??
Japan: 1570s, via Portuguese Japao, Dutch Japan, acquired in Malacca from Malay Japang, from Chinese jih pun, literally "sunrise" (equivalent of Japanese Nippon), from jih "sun" + pun "origin." Japan lies to the east of China. Earliest form in Europe was Marco Polo's Chipangu.