Sei is a Japanese office lady in her twenties who was summoned to Salutania by the Saint Summoning Ritual together with Aira Misono. Her saintly powers include a fifty percent boost in the efficacy of anything she makes using her power. Sei was not immediately recognized as the Saint at the conclusion of the summoning ritual due to her appearance. Offended by the affront, Sei does not reveal that she is actually the Saint (she confirms this in the LN when reading her own status board). During her early months working at the Medicinal Flora Research Institute, her sainthood is nearly found out multiple times due to some accidental scenes with her research. Sei is only publicly acknowledged as the Saint after many people have seen and attested to her abilities. She likes to cook and make cosmetics in her spare time. She owns a cosmetic business in the capital.

(Source: The Saint's Magic Power Is Omnipotent Wiki)