Tomomi Kawaguchi (河口 友美, Kawaguchi Tomomi) is a Japanese screenwriter who also does setting production. She is employed by Wit Studio. Before entering the the anime industry she worked as a dental hygienist.
There was a popular band with four students. After the band was offered a major contract, they broke up after a minor mistake. 6 years later, they are living their lives in their late twenties with troubles: Marriage, work, human relationship. They meet again and finish a song that they couldn't complete.
The three brothers discover that the human experiment banned after destroying the "Orochi", is still going on to secretly revive the evil snake. They also find out that some ex-members of the Yamainu (the Japanese military unit formed to kill the snake) are behind this conspiracy. The brothers fight together again in a battle against the military.
Fuma ninja clan is a secret ninja tribe that is waiting for the "Orochi" (gigantic snake) to resurrect for generations. Shirasu and his twin brother Ichiu grew up in this viscous environment and this tells how they become the leaders of the clan.
