蒼き森の時使い

When apprentice magician Nora wakes up, she finds herself in an unfamiliar room. Her mentor's guard, Eric, is also there.

"We've been transported a hundred years into the past."

It seems Nora has lost a few days' worth of memories in an accident and using Alfred, her mentor's magic, managed to travel back in time.
Now there is only one question. How can they return to the present?