Ren Mikase starts for Handelsoberschule Shimokawa ( Shimokawa Shōgyō Kōtō Gakko ), where she is a student. She took part in an FIS race for the first time on March 4, 2016 in Sapporo and made her debut in the FIS Cup on July 1 and 2, 2017 in Villach , where she finished 24th and 16th. Her next competition participation on August 18 and 19, 2017 in Oberwiesenthal was also her debut in the Continental Cup , in which she took third place directly on the podium and 22nd place.