Fay Tonpou is a Banbetsu (half-man half-animal) who became a mercenary. He is contacted by a young girl who gives him a very special mission. She is in possession of a yeast that would allow to distill a very special alcohol, the Dream alcohol. Eager to recreate the alcohol that has not been manufactured for decades, she asks him to protect her in order to safeguard the precious yeast that she always keeps it on her...