Coding Help Custom language's font didn't show up

[moffy]

For some reason, I really need a custom language mod for Japanese language.
So I try to make one, but it didn't work...
I attached the zip file here. ( It looks a little messy because I added many comment out sentences. Sorry if it bothers you. )

When I run game with this mod, there is no error log.
But Japanese font and some English font both didn't show up.

I feel like I missed some font.xnb file to load? But I'm not sure...

What I want to make is a custom language mod that only changes this part:
"LanguageCode": "jp",
to this
"LanguageCode": "JpSub",

Except that part, I want work this mod just like vanilla game does.

Could someone help me with this...?
I'm soooo glad and appreciate if someone could help me about this ;-;

P.S.
I edited this post.
If it makes you confuse, I'm sorry...

P.S.S.
Reason why I want to make this mod is I need display Japanese font while game runs in English.
Since I made custom NPC mod in Japanese with tons of dialogue sentences, I need such condition...