Plot: Chivalry of a Failed Knight is a Japanese light novel series written by Riku Misora and illustrated by Won. The story is set in a fantasy world where the titular "failed knight" Ikki Kurogane meets Stella Vermillion, who is considered a prodigy. Wikipedia
Plot: A color-blind girl from a family of mages travels back in time to 2018 and attends high school with her grandmother's younger self on a quest to get in touch with her closed-off emotions.