Hydra is the story of a former cop infiltrating the mob so that he can get his revenge over them for killing his mother & father while leaving his sister in a vegetative state.

In a time when giant department stores and supermarkets dominated the Japanese retail industry, two businessmen, Toshifumi Suzuki and Hideo Shimizu, discovered a new type of small retail store flourishing in America - the Seven Eleven. Called a “convenience store,” it was a concept new to the Japanese. Intrigued by this new idea and convinced that it would succeed in Japan as well, the two men put together a project team of fifteen members, all virtual novices to the retail trade, to bring this venture to their land. Staking his entire livelihood, young store owner Kenji Yamamoto volunteered to convert his family-owned liquor store into the first Seven Eleven in Japan. The hardship of negotiations, the oil shock, the struggle to cope with inadequate space were all met with resolve and innovation, culminating in what is now called the retail revolution! (Source: DMP)

One day, a 15-year-old girl comes into 'hard-boiled' detective Kataoka Heihachirou's office. The girl, Mizunomori Taira, gives him the shock of his life when she announces that he is her father! Her mother, Seiko, had died in a traffic accident, and Taira had decided to seek out the father she had never met. Heihachirou may be crass, sloppy, sexual and have no idea how to care for a daughter, but he takes her in. Taira and her "heart-boiled" detective papa begin their daily life together, a life neither of them could have expected!