Vector announced the service end of the Magic Game of Calva PC browser game. You can play with it until Juyl 27, 2017 (15:00 – local Japan time) and after that you can’t login to the game. You can buy diamonds until June 26, 2017 and the service support going to be available until August 28, 2017.
You can read more details about the service end in here: http://game.vector.co.jp/support/rule/#rule_vg