I see you use the script_latin patch (otherwise you wouldn't have the horizontal balloons). And I see in the title bar "Ver1.02b". So, you just need to update your game. And ensures thcrap is up to date as well, by either running thcrap_configure, recreating your patch configuration, and running the game 2 times, or by running the game, waiting a few minutes, then re-running the game 2 times (yeah, we have plans to make the update procedure easier).
I fixed it a week ago, but I fixed it on v1.03, and I didn't bother backporting the fix to v1.02b.
But if you still want to know how to do it without thcrap, I'll throw a bunch of resources.
First,
https://drive.google.com/drive/u/0/folders/0B1jzCIkoNdTRNFYwQVlJaDdQZUk. That's a google drive where I put a lot of stuff I worked on during the ULiL patching. You will be interested in the "Binary hacks" document and the "D3DX9_43 th145" directory. They contain everything I did to make ULiL able to read custom pak archives. Of course you will need to adapt a few things for AoCF. Btw, for removing all the anti-hack things with thcrap, I used an easier approach and just removed the related functions, by adding a ret at the beginning of them. The addresses of these functions are th155.exe+0x12e820, th155.exe+0x130630 and th155.exe+0x132af0. Just replace the byte at these addresses with c3 (the files thcrap uses for this are
https://github.com/thpatch/thcrap-tsa/blob/master/base_tasofro/global.js and
https://github.com/thpatch/thcrap-tsa/blob/master/base_tasofro/th155.v1.03.js).
Next, you will need to replace the bitmap font with one having korean support. You may want to look at this:
https://github.com/brliron/135tk . That's a Github repo where I try to gather a lot of tools for HM, ULiL and AoCF. You'll be mostly interested in the bmpfont directory. It contains tools to create a bitmap font to the format used by the game (but it only creates fonts with unicode metadatas, while the game uses shift-jis metadatas. If you feel like fixing it, I accept pull requests).
And finally, because you may want to use unicode yourself - or maybe, at least use a korean encoding, I'll drop the files used by thcrap for unicode support:
https://github.com/thpatch/thcrap-tsa/blob/master/script_latin/th155.js,
https://github.com/thpatch/thcrap-tsa/blob/master/script_latin/th155.v1.03.js and
https://github.com/thpatch/thcrap/blob/master/thcrap_tasofro/src/th155_bmp_font.cpp#L114. And if you're interested, here is the font used by thcrap:
https://github.com/thpatch/thcrap-tsa/blob/master/script_latin/th155/data/font/talk_font.bmp.pngAnyway, the 1st paragraph should be enough for you. Don't forget that the fix in thcrap works only if you have everything up to date, and if you use the script_latin patch.