Seven Senses of the Re'Union

Miaka, a junior high school student in Tokyo, has normal problems: fights with her mom, entrance exams, and deciding where she's going to go eat with her friends. But when she finds a mysterious book in the library, her life is changed forever when she and her best friend are transported inside!

Kagami Sakamori was one of the top players in the VRMMO Ark Earth Online as Danblf, a veteran summoner with the gravitas to match his elite status. When he falls asleep playing one day, he's transported to a world where the game is reality—but instead of his all-powerful avatar, he's stuck in the body of a cute young girl! He can't let anyone know that this little cutie is really Danblf, so he takes the name “Mira” and claims to be Danblf's disciple. If this gets out, he'll never live it down!

One day, Mitsuha falls off a cliff and is transported to a medieval Europe–type world! After a near-death encounter with a pack of wolves, she then realizes that she's able to transport between two worlds—this one and her own. Taking advantage of this ability, Mitsuha decides to live in both worlds and calculates that she'll need 80,000 gold coins to be able to retire! Mitsuha now has to come up with different ways to collect her gold coins!

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.