Update: Natsume has confirmed that the game is coming to the west as River City: Knights of Justice, and that it will be a 3DS eShop exclusive. It would seem that the Japanese setting will be switched for a European setting.
Original story: Natsume appears to be teasing a western release for the 3DS title Downtown Nekketsu Jidaigeki, a spin-off from the series known as "River City" in this part of the world.
The company posted the following tweet which references the "Barf" comment from River City Ransom - the old-fashioned phrasing highlights the fact that Downtown Nekketsu Jidaigeki is set in the past:
It looks like we could have another game to add to the 3DS library in 2017. Will you support this release with a purchase? Let us know by barfing in the comments section below - just make sure you clean up after yourself afterwards.