Coming Spring 2017
The teaser site has a report in newspaper-like fashion, stating that two mysterious holes measuring 90cm appeared in town. According to the 27-year-old fisherman bro, he discovered it early in the morning and was surprised to find the holes with a mysterious shape. Investigations will continue.

That said, the game is being developed by Select Button.
http://www.siliconera.com/2017/02/16...s-spring-2017/
http://www.apppokemon.com/koiking/
http://selectbutton.jp/