Dungeon-dwelling alchemist, Crain Arbalest.

Day and night, Crain constantly manufactured items, weapons, and armor through gathering, synthesis, and enchantment.

All of it was for his friend, the hero Pierre.

Unable to become an adventurer due to a severe injury, Crain simply wished to aid his friend who was fighting for world peace.

One day, visiting the royal capital for the first time in ages, Crain discovered his favorite shop was gone.

He learned it had been driven out of business by a new establishment.

That store was "Hero Pierre's Shop."

Peeking inside, Crain was astonished.

Everything on sale in the shop was nothing but items Crain had given to Pierre.

He confronted Pierre about his reselling scheme, only to be thrown out by an enraged Pierre.

Just then, Crain encountered the princess.

"I've finally found you, Crain!" The princess embraced him.

When she was a student, Crain had saved the princess's life, sustaining a severe injury to his dominant arm in the process.

Now a Saint with awakened healing powers, the princess began to heal Crain's dominant arm.

Using his inherent knowledge to bring down the profiteering hero and having regained the use of his dominant arm, Crain embarked on a leisurely journey with the princess.