The creator of the Senran Kagura series said he wanted to release Shinobi Refle: Senran Kagura outside of Japan, but as of right now, it looks like that might not be happening. Marvelous has stated that Shinobi Refle: Senran Kagura is currently only planned for release in Japan. If you want to see this change, hit up Marvelous on Twitter and let them know!
UPDATE - Here's another statement from Marvelous on the status of the game, just for clarity.
This particular game is currently only available in Japan (was released today in Japan) & at the moment we have no news to share regarding a western release.— Marvelous Games (@marvelous_games) November 24, 2017
If this changes we'd be sure to let everyone know :)