Angels shed tears and fall to the mortal world. Those tears are called lost tears. The amnesiac girl was left in the care of others, but her adoptive father was very considerate of her, even better than his biological daughter, so she was targeted by her "sister". While her adoptive father was working abroad, she overheard her "sister's" plan to drive her away, so she decided to run away from home. Who will you meet on your wandering journey?