Haneul is a 20 year old college girl that could be considered as an outcast at her college. She doesn’t even have any friends. She is always alone and by herself. An angel from Heaven, Kyungsoo, who is charged as her guardian angel, felt pity of her and so he decided to come down to Earth to help her.

Each angels have their own special power. One of the angels has a power of teleportation, Kai. The angel with teleportation can teleport to anywhere he wants—Earth, Heaven, Hell or Fairyland—easily. So, Kyungsoo asked for Kai’s help to go to Earth.

Another angel named, Suho, who is one of the Five Guardians of all the guardian angels in Heaven tried to stop Kyungsoo because angels can’t simply go to somewhere they want especially Earth. But unfortunately, it is not successful. Instead, he, Kyungsoo, Kai and 9 other angels near them were teleported to Earth right in front of Haneul's house. There they fought each other about the mistakes.

But they had no choice other than to stay on Earth for Kai refused to teleport them back to Heaven. So, they disguised as 12 college students who want to rent rooms at Haneul small house where there are—fortunately—rooms for rent. She’s living alone in Seoul and needs money for her college and expenses so she rent the 3 rooms in her house to them.

And, she doesn’t even know that they are angels.

      Twelve Angels      

Suho -- Water

Kai – Teleportation

Kyungsoo – Earth

Baekhyun – Light

Chanyeol – Flame

Sehun – Wind

Tao – Time control

Kris – Flight

Lay – Heal

Xiumin – Frost

Chen – Lightning

Luhan – Telekinesis