Inu no Nana is one of twelve guardian angels tasked with protecting Gorō Mutsumi, serving as the reincarnation of a dog who was once his beloved pet. Her past life began on January 11, when Gorō named her after a friendly female neighbor. She delighted in accompanying him on walks.

When circumstances compelled Gorō to move to an apartment that forbade pets, his parents, occupied with running an inn, could not care for her. A friend offered to take the dog in, and though Gorō agreed, she struggled to adapt. After his move, she ran away from her new owner and was later discovered deceased outside Gorō’s apartment, having succumbed to over-exhaustion in her attempt to return to him.

As a guardian angel, she retains a fear of becoming lost, a lingering trait from her death. Her personality is tomboyish, and she enjoys taking walks as a cherished hobby. Her favorite color is violet.

She stands 121 centimeters tall, with measurements of 62-53-64 centimeters in the first season and 64-55-65 in the second. Inu no Nana is part of a close-knit group of twelve angels who refer to one another as sisters and share the common goal of safeguarding Gorō and aiding him in overcoming his misfortune.