1 connect to you osmc in ssh
2 go in your skin folder, default is /usr/share/kodi/addons/skin.osmc
3 open file Font.xml in folder 16x9
4 append the following text to specify a new fontset:
XLarge
arialuni.ttf
0.95
0.94
48
Large
arialuni.ttf
0.95
0.94
43
Med
arialuni.ttf
0.95
0.94
38
Small
arialuni.ttf
0.95
0.94
33
XSmall
arialuni.ttf
0.95
0.94
28
Clock
arialuni.ttf
0.95
0.94
120
font13
arialuni.ttf
0.95
0.94
21
5 replace arialuni.ttf by your font but this one looks like Arial and supports asian characters.
Good luck!