I, Liz, was a saint. One day, my half-sister Aria, who had eloped to a neighboring country as a saint loved by spirits, returned, causing me to be banished and nearly killed. I became a child due to a demon king's potion, escaped to a neighboring country under a different identity, but... The one who picked me up was Lord Deash, known as the ruthless duke. I was scared that I would be killed if my true identity was revealed, but the people around me were kind. In the meantime, I learned that something terrible was happening in this neighboring country. Aria had said that it would be good if the spirits disappeared from this country, making magic difficult to use. For my gratitude, I will return as an alchemist and help the duke and others.