The story is set in 1955 in Kokuga, Hofu City, Yamaguchi Prefecture. One thousand years ago it was the site of the ancient capital, Suo no Kuni, and traces of the Heian Period (year 794-1185) are passed down to us in the form of ruins and historical place names. The protagonist is Shinko, a third grade elementary school student, who was born and raised in one of the town's venerable families. She is a little girl whose characteristic is a strange curl on her forehead (she calls it her "Mai Mai"), and her love for playing in the fields. On the other hand, her secret joy is to imagine and to daydream about the world of one thousand years ago. Her fantasies travel far into the days of the Heian Period... One day, a girl called Kiiko transfers from Tokyo and enters Shinko's class. This girl from the big city has difficulty feeling at home in this small town, but gradually her friendship with Shinko deepens. Before long, the two of them become engulfed in a strange incident of one thousand years earlier...?!

Fujiko Mine is on the run with Gene, a boy who knows the location of a stash of $500 million dollars that his deceased father embezzled from the company Godfrey Mining. The boy is targeted by Bincam, an assassin hired by Godfrey Mining with a mysterious ability that allows him to bend a person’s will.

(Source: ANN)

In 18th century Paris, a coffin is found floating down the Seine River. It carries the corpse of noblewoman Lia de Beaumont: a spy of King Louis XV, and whose younger brother Charles d'Eon has just been knighted. When several disappearances occur throughout Paris, the young knight believes that they are somehow connected to his sister's death. Hoping to find her killers, d'Eon joins the secret police to investigate the incidents. Following the clues, they piece together that a conspiracy between members of the French and Russian nobility, spurred on by a cult, may be behind the disappearances. D'Eon concludes that Lia may have uncovered the truth while on a mission and was killed as a result. That night, the secret police are to arrest the Duke of Orléans on suspicion of being the mastermind. One of their own transforms into a demon called a Gargoyle and massacres the group. D'Eon attempts to rescue the sole survivor, only to find that he too has been transformed. During the ensuing battle, d'Eon is possessed by Lia's vengeful soul, who takes command of his body and slays the Gargoyle herself. In the aftermath, d'Eon must gather allies to discover the depth of this supernatural conspiracy. [Written by MAL Rewrite]

Following the line of the precedent OVAs (of the same name) This anime goes around the normal lives of some elementary school (5th grade, 2nd class room) kids and their adventures, while turning to teens. Their games, stupid jokes, and the misunderstandings around their premature attraction to the opposite sex. Ryota Satou is the main character here, but his friends are almost as important as him since the school wouldn't be the same without them, especially the girls who the majority of time appear to be mature by their ages but in the ends they are as childish and even more "dangerous" than the boys. (Source: ANN, edited)