When high schooler Tazuna happens to hold hands with a girl in a lab, the two form the contract of Hand Shakers - couples who must fight in otherworldly battles to have a wish granted by God. There's just one catch: Letting go means death.

Those who receive the Revelation of Babel must overcome many battles and trials. By grasping the hand of their special partner, these "Hand Shakers" transport themselves to the realm of Ziggurat, an alternate dimension where time no longer exists. Each pair of Hand Shakers must battle it out for the right to meet with God, who will reward them by granting them a single wish. Tazuna Takatsuki, a high school student with a penchant for fixing things, is one of these Hand Shakers. After receiving a request for repairs from Professor Makihara of a nearby university, Tazuna stumbles upon Koyori Akutagawa, a bedridden girl that reminds him of his deceased sister Musubu. Remembering her dying wish to never let go of her hand, Tazuna grasps Koyori's hand and awakens his power as a Hand Shaker. However, Koyori's life is directly tied to her status as a Hand Shaker, meaning if Tazuna was to ever let go of her hand she would die. With meeting God being their only hope for saving her, the duo must find a way to make their unique powers mesh together, overcome the opposing Hand Shakers, and make their wish come true.—MAL Rewrite

Tazuna is a high school student, living in Osaka, who loves to fiddle around with machines. One day, he receives a repair request from an university laboratory. He accepts the request and ends up meeting a girl named Koyori, who has been bedridden for a very long time. Suddenly, Tazuna and Koyori get pulled into a whole different world called "Ziggurat". In this world, there are Hand Shakers, two people who touch hands and create the Nimrod. Their goal is to defeat other Hand Shakers in order to gain an audience with "God", who will grant them wishes. Protect with your own Hands!.—Crunchyroll

Fighting for the chance to confront God is hard enough, but high school student and genius mechanic Tazuna has it tougher than most. When he happens to hold hands with a girl in a lab, the two form the contract of Hand Shakers-couples who must fight in otherworldly battles to have a wish granted by God. There's just one catch: Tazuna's partner, Koyori, will die if she lets go of his hand. With every challenge they face in the alternate dimension known as the Ziggurat, the two grow stronger. Little do they know that a secret from Koyori's past might just be their undoing.—Funimation