Subtitle Edit 3.6 has great OCR for ripping Japanese captions
As you can see, you can download something called Tesseract 5 which seems to have pretty good Japanese OCR recognition. I'm ripping the subtitles for RealXTime for the wiki now
To set it up:
https://github.com/SubtitleEdit/subtitleedit/releases
1) Set OCR method to : Tessseract 5.00
2) Change language to Japanese (you will need to download it first)
3) Hit Auto OCR and let it run
