The PC-98 era of Touhou is the first of the two Touhou eras lasting between 1995 to 1998 with games 1 through 5.

The games in this era were made for the PC-98 computers, which were popular in Japan before the era of Windows computers.

While some characters carried over to Windows Era, most content from PC-98 is ignored in Windows. PC-98 is more or less considered to be canon until something in the Windows Era contradicts it.

Despite PC-98's being less well-known, there are many fanworks which include it and there are quite a few characters people want to make a return in the Windows Era.