Yuuta Hibiki wakes up in the room of Rikka Takarada and notices two things: he has no memories, and he can hear a mysterious voice calling his name from a nearby room. On further inspection, he finds a robot—which introduces itself as Hyper Agent Gridman—behind the screen of an old computer. Much to Yuuta's surprise, Rikka cannot hear Gridman, nor can she see the ominous monsters looming over a thick fog as it envelopes the town outside. Another giant monster materializes in the city and proceeds to wreak havoc. Amidst the confusion, Yuuta is once again drawn to the old computer and merges with Gridman. Suddenly, he appears in the middle of the battle and is forced to fight the monster. Together with Rikka and fellow classmate Shou Utsumi, Yuuta forms the "Gridman Alliance" to defeat the monsters plaguing the city and find whoever is responsible for their emergence. [Written by MAL Rewrite]

In the distant future, a majority of humans have left the Earth, and the Galactic Alliance of Humanity is founded to guide exploration and ensure the prosperity of mankind. However, a significant threat arises in the form of strange creatures called Hideauze, resulting in an interstellar war to prevent humanity's extinction. Armed with Chamber, an autonomous robot, 16-year-old lieutenant Ledo of the Galactic Alliance joins the battle against the monsters. In an unfortunate turn of events, Ledo loses control during the battle and is cast out to the far reaches of space, crash-landing on a waterlogged Earth. On the blue planet, Gargantia—a large fleet of scavenger ships—comes across Chamber and retrieves it from the ocean, thinking they have salvaged something of value. Mistaking their actions for hostility, Ledo sneaks aboard and takes a young messenger girl named Amy hostage, only to realize that the residents of Gargantia are not as dangerous as he had believed. Faced with uncertainty, and unable to communicate with his comrades in space, Ledo attempts to get his bearings and acclimate to a new lifestyle. But his peaceful days are about to be short-lived, as there is more to this ocean-covered planet than meets the eye.

The legend of the Divine Gate is a story told to young children that depicts the merging of the living world, the heavens, and the underworld. "Adapters"—people born with unique elemental abilities gifted to them from the union of these worlds—formed the World Council, an organization which controls the chaos of the Gate by portraying its legend as nothing more than a myth. These Adapters train in a special academy owned by the World Council that allows the students to hone their skills. Aoto, a teenage boy with exceptional water powers and a tragic past, rejects the offer to join the academy numerous times—until he is successfully pressured by the energetic wind user Midori and stubborn fire user Akane. Together, with the World Council and their mysterious leader Arthur, they seek out the Gate in the hopes of uncovering the truth. But in order to reach their goals, they must unite and overcome their own despair while dealing with behind the scene mischief. [Written by MAL Rewrite]

While spending the summer at his aunt's house, the young but sickly Shou makes an amazing discovery: after following the house cat into the bushes, he gets a glimpse of a miniature girl about the size of his finger! Calling her kind "Borrowers," as they survive on tiny bits of human possessions, the girl introduces herself as Arrietty. As he discovers that she lives in the house basement with her parents, Pod and Homily, Shou becomes imaginably excited at the idea of such unique neighbors.

However, he fails to understand the adversities they face on a daily basis. In addition to keeping their existence hidden, they must also embark on perilous adventures into human territory, from the house to the outdoors, in order to make a living. Despite her parents' warnings, Arrietty befriends Shou, stirring up unexpected events that may change their lives forever.

Delighting the eye and conquering the heart, the breath-taking story of a friendship transcending the tensions between two different human kinds begins.