Not Mandarin, but some unspecified southern dialect (probably Fujianese/Hokkien, where it's Jitpun). If Mandarin had been involved, we'd call Japan something l

Not Mandarin, but some unspecified southern dialect (probably Fujianese/Hokkien, where it's Jitpun). If Mandarin had been involved, we'd call Japan something like Arben (Riben) in English.