Lucia Arca able to use  magical incantation “Soap!” I can only cause soap bubbles to appear.Through this, she perform the duties of a laundry girl employed by the royal castle.one day she found out it also has the additional effect of purifying monsters during the monster outbreak.She forced to accompany the journey to purify the Heavenly Crystal Tree, the companions include His Highness the crown prince, a saint summoned from another world, the commander of the strongest knight brigade and his adjutant, the Dragonslayer Hero, the Academia institute’s top sorcerer, etc. etc. etc. 

Surrounded by these prodigies, once the Heavenly Crystal Trees’ purification safely ends, she hopes her daily life will return to normal