This is a sequel to the former reports in this journal on PRINSE, a simplified peace research document retrieval system on the personal computer. The present one reports on its important latest improvements. The primary purpose of the improvement is to enable the program to deal with Japanese documents, which consist (mainly) of so-called 2-byte characters. In addition, many other additions and improvements are made, including such facilities as execution of user-defined macros, on-line manual, user customization, use of tags and so on.