A spoiled and pampered Lady Hero, a noble and honest Female Knight, and a gentle Onee-san like female Saint-sama. Along with the three women, the sole male in the group the black magician Falsa, on a journey to defeat the Demon king. He is one of the Four Heavenly Kings of the Demon King army at the same time he is participating in the hero party as the head of the court magician. Every day he fights as a human along with the hero party in the day and works as a demon in the Demon king army at night. 「 I just want to earn the minimum money to live! I don’t want to get promoted and get busy! I just want to stay in a peaceful country and read every day. 」 It was wishful thinking for Falsa, the half-demon, and half-human, as the people around him valued him highly, leading him to embark on a path of success from which he cannot return. Falsa continues to work every day, fearing when his true identity will come out.