Suehara Maru is childhood best friends with one of Hozumino High School's most popular girls, Kuroha Shida. Cute, outgoing, and affectionate, Kuroha is the perfect older sister type. She has boys constantly begging at her feet to be with her. Yet, when she confesses to Suehara one day, he immediately rejects her; he just can't think of her in that way! Besides, he already has his sights set on his first love—school idol and renowned author Shirokusa Kachi. Suehara believes that he has a chance with Kachi after one fateful meeting, but soon, he finds out that Kachi has a boyfriend! With his dreams now shattered, Suehara agonizes over what could have been. That is, until Kuroha approaches him with a proposal: let's get revenge.

The true end arc of Ore no Imouto. These four episodes branch out after the 11th episode of the main TV series and present an alternative version to the end of the TV series. These episodes contrast with the good end arc of the TV series, which was an original ending written for the anime, and instead closely follows the original story from the light novels.

Humanity is facing extinction. In a snow-covered world where water has become scarce, the last habitable lands are located at the feet of gigantic Orbital Trees scattered about the desolated Earth. According to a legend, there exists a sage who knows the secret to producing abundant quantities of water to save mankind. Ririha, the princess of Atland, uses an organic hot-air balloon to climb to the top of an Orbital Tree in hopes of meeting her country's savior. Once she reaches the Canopy—an area that appears to be an infinite window of transparent ice—she meets Kaina, one of the last men alive on the Canopy. However, she can not find the man she was looking for. Unable to return by herself to her country, the princess finds a helping hand in Kaina, who is eager to explore the surface world that he thought was empty. As Kaina learns about the war against Ririha's country, the antagonistic technologically advanced nation Valghia, and other perils of the surface, he realizes that his escorting mission will prove more difficult than he imagined.

The 1st BD & DVD volume of Osomatsu-san will have a new episode, replacing episode 1 of the original series which was removed due to the fact that it contained multiple parodies. It has been pulled entirely from streaming sites and the Japanese Blu-Ray release. This replacement episode is sometimes numbered episode 3.5 as listed on the home-media release, as it's chronologically placed after episode 3 (originally TV episode 4).