The day before her birthday, Akane is asked to retrieve her birthday present from her aunt Chi's shop. While looking around, she chances upon a mysterious slab with a hand-shaped cavity in it. Curious, she places her hand in it, and—to her surprise—it fits perfectly. The next thing she knows, a strange alchemist named Hippocrates and his apprentice Pipo appear, calling Akane the legendary "Goddess of the Green Wind." The two eccentrics claim to be from a different world connected to the shop's basement. With the peace of their world in jeopardy, Hippocrates and Pipo seek the help of the only one capable of saving it from destruction: Akane. Forced to accompany them on a journey to restore the land's harmony, Akane—with her aunt in tow—sets off to discover a magical new place. [Written by MAL Rewrite]

1960s --- Tokyo. Shin is a boy who lived happily despite being poor, loses his mother who is his only family member, and falls into deep misfortune. Itsuki, a boy who saves Shin also lost his older sister. Those two boys are joined by Tae, a girl who can see youkai and together with Shin's guardian spirit Suu-san and new Youkai such as Nekomata, they take on a mysterious incident in order to retrieve the souls of their precious family! And what is the shocking truth that awaits them...!? An origin story for how Lord Enma became the rule of the Yomakai. (Source: Wikipedia, edited)

OVA bundled with 4th volume of manga.

Three weeks after the incident that left Captain Napolipolita's ship balancing on top of Graviton City, A-Ko and the gang go on summer vacation. While A-Ko ponders losing some weight and B-Ko devises another plan to defeat her redheaded rival to win C-Ko, Napolipolita and Spy-D experience severe homesickness - begging for a way to return to their home planet. Meanwhile, Hikari Daitokuji - B-Ko's father and the CEO of the Daitokuji Financial Group - arms the local military with new mecha to attack Napolipolita's ship and obtain its advanced technology.