: Some Japanese games require your system to be set to Japanese Locale or run through Locale Emulator to prevent text from appearing as gibberish (mojibake) or crashing on startup.
Because RAR archives use a "solid" compression method, the data is often woven together across the volume set. The dictionary (the map of where files are located) usually resides in the first part. Therefore, to access the content within these files, you must possess the complete set (Part 1 through the final part) in the same directory. H-RJ01278558.part2.rar
It sounds like you're referring to a multi-part RAR archive ( H-RJ01278558.part2.rar ) and noting that it's part of a archive. : Some Japanese games require your system to