From what I have read here, there is a huge problem with getting licenses for Japanese dramas, really complicated. There are way less shows coming from Japan than other countries, and the show you are talking about is not licensed in any country.
Honestly what I love in Viki is not only the comments, but the subs. You can turn them on, off, and switch languages. As someone who is learning Japanese, I just can't find any shows elsewhere with Japanese subs or even just without English subs. I currently watch Kdramas with subs in Japanese, but hearing and reading would make me learn better.
I wish this whole issue will get solved or something, I really want more Japanese dramas.
You can always try to request the show here: Request form