thrae

Hello there,
The engine is WillPlus/AdvHD, so you'll have best luck looking for compatible tools (Pulltop)
There are numerous people who worked on both scenario (retranslation) and graphics patches for If My Heart Had Wings (IMHHW) or koirizo DAT is probably just the extension for bitmap files. ARC is the extension for archives (but it is NOT required to repack modded files IIRC, you just put them in the EXE directory) [1] See thread
and (WillPlus)
 
[2] https://github.com/ZudoMC/AutoSpriter
[3] https://github.com/Inori/FuckGalEngine/tree/master/AdvHD
[4] https://github.com/Amarillys/MaikzJsRepo/blob/master/advhd-mkz.js
[5] https://github.com/marcussacana/WillPlusManager
 
 
MeruP has private tools apparently, so you may want to ask (nicely).

You may download the v0.4 here: https://web.archive.org/web/20171201163843/https://tlwiki.org/index.php?title=File:Yuno_arctools.zip