Supported Japanese character sets are:
JISX0201-1976
JISX0208-1990
JISX0212-1990
JISX0212-1990 is not supported in the ja_JP.PCK locale.
Vendor Defined Character (VDC) and User defined Character (UDC) are also supported. VDCs occupy unused (reserved) code points of JISX0208-1990 or JISX0212-1990. UDCs occupy the same code points as VDCs except the code points are for VDCs.