A spinoff of Ore no Imouto ga Konnani Kawaii Wake ga Nai following Kuroneko's route. This manga is a new story based on volume 15 and 16 of the Oreimo lightnovel written by the original author Tsukasa Fushimi. Not to be confused with Ore no Kouhai ga Konna ni Kawaii Wake ga Nai, which is another spinoff.

Manga adaptation based on Kuroneko's story, which starts in the 5th light novel.

Kyosuke Kosaka, a normal seventeen-year-old high-school student, hasn't gotten along with his younger sister, Kirino, in years. For longer than he can remember, Kirino has ignored his comings and goings and looked at him with spurning eyes. It seemed as if the relationship between Kyosuke and his sister, now fourteen, would continue this way forever. One day, however, Kyosuke finds a DVD case of a magical girl anime entitled Hoshikuzu Witch Meruru (Stardust Witch Meruru), which had fallen into the entranceway of his house. To Kyosuke's surprise, inside the case, an adult video game entitled Imoto to Koishi yo! (Love with Little Sister!) is hidden.

Yamada Elf Senseis Route. Someone Please scanslate this. Its only 15 chapters

This is the Ayase route of the Oreimo storyline.

From ANN: The "new sibling romantic comedy" revolves around Masamune Izumi, a light novel author in high school. Masamune's little sister is Sagiri, a shut-in girl who hasn't left her room for an entire year. She even forces her brother to make and bring her meals when she stomps the floor. Masamune wants his sister to leave her room, because the two of them are each other's only family.

A collection of artwork by several artists, 4-komas, omakes, and fanfiction stories of the Toaru Majutsu no Index universe.Original released as a bonus special edition of the release of the 5th manga volume of Toaru Kagaku no Railgun.

The "if" series was released to tell a Happy End story of each heroine with protagonist Kyousuke Kousaka.

Chiaki is handsome, academically gifted, athletic, and born into a wealthy family with a beautiful sister. Despite his seemingly perfect life, he faces a persistent problem: he's never been lucky in love and struggles to capture the attention of girls. Determined to turn things around in high school, he wakes up one morning to a surprising transformation—he has turned into a girl!He is shocked to find out that he has lost the appearance he was so proud of, but when he looks in the mirror, he sees a very cute girl in the reflection. He immediately goes to show it off to his twin sister Kaede, who happens to be very popular with the girls, but there is also something very strange happening to her...(Source: Kadokawa, translated)