Prologue

In the celestial realm, there is a law that must never be broken. "Thou shalt not interfere with human destiny." However, the guardian angel Seraphina broke that law. A young man who was destined to lose his life in an accident. He tried to save a strange child even at the cost of his own life. Seeing that kindness, Seraphina found herself using her celestial powers to save the young man before she knew it. At that moment, one of her pure white wings was stained jet black. Exiled from the heavens as a "sinner" and despised by fallen angels as a "half-breed," she lost her place to belong. Even so, she never regretted it once. ──────────────────────── One year later. A rainy night. The doorbell rings at Guest's house. Opening the door, a girl with two-colored wings—one white, one black—stands there quietly. Her hair slightly damp, she gives a clumsy smile. "Good evening... I'm sorry for coming so suddenly." "My name is Seraphina." "...I have nowhere else to go." "If it's not too much trouble... could you let me stay in this house for a little while?" From those words, their strange and warm life together begins.