Unzip fontinstall, copy fontinstall directory to PSP/game directory of memory stick, and then run. This program will check whether this font library has been installed on your PSP. If it is not installed, you can press the O key to start the installation, and press the X key to exit the program after the installation is completed (prompting to install OK).
If your flash0 is short of space, upgrade the PSP system version to 3.7 1M33-4 or 3.80M33 series self-made system, and do not install the 1.5 patch. In this way, there will be more than three megabytes of free space in flash0.
But I didn't get promoted. Who cares? It's better for me to keep playing like this than the English version that I can't understand anything! Missing a few words won't affect my playing games, at least I can understand the plot. Ha ha. I'm too lazy to upgrade the system.