Dennis’s parents are a couple of scientists who have genetically modified all their children except Dennis into speical hybrids. One day, the secret island laboratory was discovered. The parents were arrested by the police for conducting illegal research in their own house. The children were relocated to another island by social workers. The problem is that the four siblings other than Dennis are different from normal people. Dennis, the youngest sibling and a genius, is the only one grew up as a normal human. Can they survive in the outside world and hide their special identities? Shiyan Pin Jiating/Jikken-hin Kazoku: Creatures Family Days DVD release decision is confirmed. Please support it if you like this anime.