Tobenai Majo

From Ivyscan:

Karin and Lisette are witches who trained together when they were younger. After a long absence, Lisette has moved to a nearby forest and seems to be stealing Karin’s customers. Karin really wants to see her old friend again, but she can’t seem to get past Lisette’s apprentice, a young man named Ruin…

Volume 1 Oneshot: Meeting Place
About a student that can't say thanks to her overly enthusiastic teacher; so, she is thrown back in time to figure out that she still can.

Volume 2 Oneshot: Mission Sachiyama
About an after school program that trains modern day ninjas.