Sweet Rein (よろしく・マスター, Yoroshiku Masutā) is a shōjo manga by Sakura Tsukuba.
Kurumi Sagara is a high school student who one day bumps into Kaito, a young man who turn out to be a Reindeer.
Kaito is determined to prove that his feelings are real and not just as a result of their unique relationship.
Santas are ordinary humans who are given the task to deliver presents to children the night before Christmas.
Their bodies respond to any command their Santa gives, being able to fly and be summoned at any time to their master, regardless of their will.
They also experience heat during spring, in which Reindeers will begin attracting other humans of the opposite sex who lay their eyes on them.
Reindeers often appear as normal humans, a common feature are their vertical slit pupils.
Because of this, they're punished by being forced to wander without purpose, if they receive a fatal wound, it will be healed quickly.
She has become accustomed to loneliness as her mother passed away when she was young and her father is often away from home due to work.
She is also described as 'responsible' by Kaito's family as she assumes a level headed demeanor in most situations and diligently does her duty as Santa.
Nene became a Black Reindeer after falling in love with her fourth Santa and then disrupting his relationship with another.
Serialized in LaLa DX this manga has been published in three volumes by Hakusensha, in German by Tokyopop, and in English by Viz Media.