Don't tell me I'm History's Weakest PreCure??

Unable to control her new Precure powers, Tsubomi fails in rescuing Erika's Heart Flower and is nearly killed by the Desertrian, but is saved by a mysterious man before losing consciousness. She awakens in her grandmother Kaoruko's botanical garden and discovers her grandmother to have once been a PreCure herself. After receiving encouragement from Grandmother Tsubomi gains the courage to stand up to Sasorina, defeat the Desertrian, and restore Erika's Heart Flower. Tsubomi learns that by defeating Desertrians, she will collect Heart Seeds that will allow the withering Tree of Hearts to become healthy.