So the Japanese market had very specific requirements, that PCs could not fulfill in the early DOS days. You couldn’t just replace the character ROM on your PC and make it display Japanese text (IBM did later develop the 5550 and the JX, a derivative of the PCjr, specifically for the Japanese market, and later, they developed the DOS/V variant, which added support for Japanese text to their PS/2 line, using standard VGA hardware, which by now had caught up in terms of resolution).
Instead, Japanese companies jumped into the niche of developing business machines for the home market. Most notably NEC. In 1981 they introduced the PC-8800 series, an 8-bit home computer based on a Z80 CPU and BASIC. In 1982, the PC-9800 series followed, a more high-end 16-bit business-oriented personal computer based on an 8086 CPU and MS-DOS. These families of machines became known as PC-88 and PC-98 respectively (Note that the ‘PC’ name here is not a reference to IBM, as NEC had already released the PC-8000 series in 1979).
I love these machines.