Evil Goddess Miku has stolen the human's light. Angel Luka just wants to help the human's in their time of need, which results in her being thrown from heaven. Somehow she survives the deadly fall. Wingless and stuck in a world where light doesn't exist she joins with Gakupo and his small group of humans, determined to stop Miku's evil reign and bring the light back.

Luke was Luka's adoptive older brother. Luka was Luke's sunshine, his whole world, the best little sister a brother could ever have. And as for Luka, Luke was her knight in shining armor. What happens when after the best summer they spent together, Luke's real mother comes to take him back? What will happen when he returns as Kaito after some years?

Luka Megurine moved to the country to live with her grandmother in the Amane Shrine. On her first day, she caught a glimpse of a purple-haired person who was hiding in the bushes in front of her balcony. Who is this mysterious person? And why does Luka's grandmother forbid Luka and this person from meeting each other?