Saga of Tanya the Evil

When a sickly young girl suddenly becomes obsessed with inventing new things, her family and friends are all puzzled. "What has gotten into Myne?" they wondered, never dreaming that the answer is not a "What" but a "Who": Urano Motosu, a book-loving apprentice librarian who died in an earthquake in Tokyo who somehow found herself in Myne's body! And since Myne's world is still in a medieval stage, where books can only be owned by the elite, the new Myne intends to do everything she can to bring her beloved books to the masses in the time she has left.

There was once a Holy Grail War waged by Mages and Heroic Spirits in a town of Fuyuki. However, one Mage took advantage of the chaos of World War II to steal a Holy Grail. Several decades have passed, and the Yggdmillennia family, who took upon the Holy Grail as its symbol, defected from the Mages' Association. Furious, the Association sent forces to deal with the Yggdmillennia, but were defeated. With the Holy Grail system changed, war at an unprecedented scale breaks out.

On a continent ruled by chaos, the Lords have the power of a holy seal that can calm the chaos and protect the people. However, before anyone realizes it, the rulers cast aside their creed of purifying the chaos, and instead start to fight each other for each other's holy seals to gain dominion over one another. Siluca, an isolated mage who scorns the Lords for abandoning their creed, and a wandering knight named Theo, who is on a journey to train to one day liberate his hometown, make an everlasting oath to work together to reform this continent dominated by wars and chaos.

Caught in a 150-year-long war, interstellar nations reach the pinnacle of strategic combat at the hands of two genius leaders. Reinhard of the Galactic Empire, and Yang of the Free Planets Alliance lead the charge from opposing fronts. Fighting is their destiny, but in this vast universe torn by political intrigue, their greatest enemy may not be each other.