I’m going to make this school my harem! When a cute girl asks Issei out, he believes his twisted fantasies are finally coming true. Too bad the girl sprouts a pair of black wings and stabs him with a spear on their first date! Saved by his school’s number one beauty, Rias Gremory, Issei is transformed into a demon and made her servant. Issei hopes to rise through the ranks of demonkind to grow powerful enough to create his harem, but in a city with fallen angels and insane priests, he’ll be lucky if he can live long enough to do it! (Source: Yen Press)

Shin High School D×D is a light novel series set in the High School DxD universe. Continuing from where Volume 25 of the previous light novel series left off, high school student-turned-devil Issei Hyoudou is still pursuing his dream to be a harem king. (Source: TV Tropes)

High School DxD DX is a compilation that consists of already published short stories on various issues of Dragon Magazine and as well as newly written ones.

A new student steps up to the gates of Kuoh Academy junior division. Zekka, a descendant of Miyamoto Musashi, wields the sword-shaped Sacred Gear "Tensei." Her goal? To make friends at Komaou Academy!? A new "DxD" series begins, guided by unique friendships and by Rias and the other high school students! (Source: Kadokawa, translated)

The historical romantic comedy follows 17-year-old high schooler Sagara Yoshiharu who one day time-travels to the Sengoku period, where all the major Samurai lords are cute girls. Yoshiharu meets Oda Nobuna, the girl counterpart of Oda Nobunaga, and begins to serve her as a substitute of Kinoshita Tokichiro, who has been dead in the world.

The world will go to ruins if i stay together with her. But still, i'm in love with her-- Haruto, a commoner magician attending the magic academy, has confessed to princess Iris from a opposing country and ends up dating her!? But as it turns out, she is sharing her body with the demon king, and the world will come to an end if she is together with Haruto-- For her sake, he will get rid of her responsibilities and will destroy the curse! (Source: Fantasia Bunko)

From matchlocks and cellphones to kimono and TV games, the cultures are blended, a modern Era with an “Inner Palace” inside the Osaka castle!? The only son of the Toyotomi Shogun, Hidekage, on mission with the inspection bureau “Carrion Cafeteria – Vulture”, infiltrated this harem where pretty girls are gathered. However, the girls he saw there, were fighting for show, watched from outside an aquarium-like glass case. Those are not regular beauties! This is the start of a never experienced before forbidden school life!

Serialization from the Dragon Magazine, the first short story collection of 「Oda Nobuna no Yabou」! A beautiful-girl stealing tea utensils appears during the tea-ceremony boom of the sengoku period? Hanbei taking advantage of the Onmyoudou which should have been extinct, Yoshiharu got 4 more little sisters and Shimazu Iehisa is in Tokyo. Furthermore the last Oni living on this land is getting resurrected!? (Source: Kadokawa)

An anthology by various authors and artists.

A side story of Oda Nobuna no Yabou which focuses on Bontenmaru, the Daimyo of Oushu and the future Masamune Date. She is a companion and bodyguard of Louise Frois and an ally of the Oda Clan. Possessing heterochromia, she also has a case of chuunibyou (8th grader adolescent delusions), believing her red eye has special powers which is hidden under an eyepatch. Like Nobuna, she also has an estranged relationship with her mother.