Makoto Niwa meticulously tallies the amount of positive and negative youthful experiences he engages in as if to grade his own life. When his parents go overseas, he moves to a new town to live with his aunt, welcoming the change and ready for a fresh start. However, as ordinary as he had imagined his adolescence to be, he could never have taken the existence of an enigmatic long-lost cousin into account. Upon moving into his aunt's house, he discovers the cousin he never knew about: Erio Touwa. Despite being Makoto's age, she couldn't be more different: Erio chooses to wrap herself in a futon all day rather than to go to school. She even claims to be an alien, and with a speech pattern and personality to back it up, any chance of Makoto's dreamt-of normal life is instantly tossed out the window. As he meets a string of other eccentric girls in town, Makoto must face the possibility of seeing his youth points in the red. However, he might be surprised by how thrilling an abnormal youth can be.

The momentous day of the opening of the new Tokyo subway, the Touto Line, has come, but a bombing incident puts all celebrations to a halt. The governor of Tokyo is caught in the blast while onboard the train, but he and everyone else present is fortunately saved by the quick thinking and actions of Conan Edogawa. Intrigued by the incident, Conan researches the governor's political history and discovers that the man was responsible for the destruction of a village in Niigata to build the Kitanosawa Dam. Believing the attack to be related to the construction of the dam, Conan, accompanied by Ran Mouri, Kogorou Mouri, Professor Agasa, Sonoko Suzuki, and the Detective Boys, decides to visit the village and investigate. There, they meet a group of locals who lived in the old village before it was torn down. However, just as one mystery leads to another, one of the locals is murdered. Suspecting that something much more sinister is afoot, Conan vows to uncover the truth behind these two incidents before it is too late.

Returning to the Digital World, Taiki and Shoutmon learn that the Bagra Army has taken it over and reformatted the world to have Seven Kingdoms, each ruled by a general. (Source: AniDB)

Dog Days takes place in the world of Flonyard, an alternate Earth inhabited by beings who resemble humans, but also have the ears and tails of specific animals. The Republic of Biscotti, a union of dog-like citizens, has come under attack by the feline forces of the Galette Leo Knights. In an effort to save Biscotti, Princess Millhiore summons a champion from another world in order to defend her people. That champion is Cinque Izumi, a normal junior high student from Earth. Agreeing to assist Biscotti, Cinque retrieves a sacred weapon called the Palladion and prepares for war. In Flonyard, wars are fought with no casualties and are more akin to sports competitions with the goal of raising money for the participating kingdoms. Cinque is successful in his role as Biscotti’s champion, but learns that a summoned champion cannot be returned to their home world. The scientists of Biscotti will endeavor to find a way for Cinque to return home, but until they figure something out, he must serve Princess Millhiore by continuing to fight as Biscotti’s hero.