After being suddenly transported to another world, Subaru Natsuki and his new female partner are brutally murdered. However, Subaru awakens to a familiar scene, meeting the same girl again. The day begins to mysteriously repeat itself.

At a high school full of unique characters, Tadano helps his shy and unsociable classmate Komi reach her goal of making friends with 100 people.

Subaru and friends finally get a moment of peace, and Subaru goes on a certain secret mission that he must not let anyone find out about! However, even though Subaru is wearing a disguise, Petra and other children of the village immediately figure out who he is. Now that his mission was exposed within five seconds of it starting, what will happen with Subaru's "date course" with Emilia?

Bell Cranell is a rookie adventurer and the sole member of his dirt-poor guild founded by the petite goddess Hestia. Adventurers come from far and wide looking to strike it big in the massive labyrinth known as Dungeon, located beneath the city of Orario. Bell is more interested in picking up girls than Dungeon-crawling, but his reality check comes sooner than expected. Saved from a brush with death by the beautiful, renowned adventurer Aiz Wallenstein, Bell falls head-over-heels and sets his sights on winning her heart, but she's not the only woman he's caught the attention of, for better of worse.