In the distant future, humanity is under attack by the Abh Empire, a race of advanced humanoid beings possessing vastly superior technology. As countless worlds fall to the Abh, mankind establishes the Four Nations Alliance—a resistance faction made up of the United Mankind, the Republic of Greater Alcont, the Federation of Hania, and the People's Sovereign of Union Planets. Seikai no Monshou tells the story of Jinto Linn. When he was young, his father—the president of Martine—sold their world in exchange for a high position in the empire. Now a young count, Jinto must learn the ways of Abh nobility and live among those who subjugated his people. Helping him is Lafiel Abriel, an austere Abh princess whom Jinto quickly befriends. While traveling to Jinto's new school in the Abh homeland, their ship is caught in a violent space battle between the fleets of the Alliance and the Abh. Jinto and Abriel are thrust into the conflict, unaware that this skirmish marks the beginning of a full-scale war between the Abh Empire and mankind. [Written by MAL Rewrite]

The story is set in the 22nd century where space travel, planet colonization and anti-gravity basketball are practically everyday things. Planet Earth has become uninhabitable, and therefore people live in colonies on the surrounding planets. On a school field trip, a mistake causes the protagonist, a young transfer student named Luna, her pet robot, and six of her classmates to be thrown through a gravity storm and crash land on a seemingly uninhabited planet. There, with Luna as their leader, the robot cat Chako, the lone wolf Kaoru, the spoiled rich boy Howard, the shy Sharla, the obedient Bell, the prideful musician Menori and the young genius Shingo must fight for their survival. But is the planet really uninhabited, or is there someone or something out there, waiting in the shadows? (Source: Wikipedia)

The everyday lives of the Minami sisters continue. Chiaki, the youngest, continues to call people idiots while worshipping her eldest sister. Kana, the middle, still can't figure out that Fujioka's feelings for her are a crush, not a grudge. Haruka, the eldest, still unknowingly avoids Hosaka's advances to invite her to the volleyball team, and after a long day of excitement, the sisters enjoy sitting at the table at their home. (Source: ANN)

The Minami residence is home to three sisters: the strict and diligent eldest sister Haruka; air-headed and lively Kana; and the youngest, Chiaki, whose sharp tongue spares no one. Living without adult supervision, the sisters share the workload of cooking and laundry, as well as the occasional romantic adventure. From combating chronic laziness to hanging out with friends, there is never a boring day in the Minami household. [Written by MAL Rewrite]