Black Gate (2004)

When Yumi Fukuzawa entered the Lillian Girls' Academy, a prestigious all-girls Catholic school in Tokyo, she never imagined she would catch the eye of beautiful and demure Sachiko Ogasawara, one of the school's most popular students. Now Sachiko has offered to be Yumi's soeur, her "sister" and guide for all her years at the academy. The whole idea has Yumi completely flustered—after all, they hardly know each other! The entire campus is abuzz with rumors about the two of them, but Yumi is conflicted over accepting Sachiko's offer. While she admires Sachiko, being her soeur would also mean constantly being at the center of the entire school's attention!

Nagisa Aoi is a new transfer student into one of the three prestigious all-girls Catholic high schools on Astraea Hill: a school called St. Miator (the other two are St. Spica and St. Lelim (known in the anime as Le Rim, for some reason). While getting totally lost on her first day, she stumbles into a clearing with a tree, and also into a girl with long silver hair. Nagisa is immediately smitten with the girl, Shizuma Hanazono, otherwise known as the Etoile of the three schools (the most idolized girl). Shizuma, after picking up a figurine dropped by Nagisa, kisses her on the forehead, leading to Nagisa fainting. After waking up in the school's infirmary, Nagisa then meets her new roommate, Tamao Suzumi. Things, however, will be getting a lot more complicated for the new student than just that.

The story takes place in Japan in the early 21st century, in an alternate reality where the Tokugawa Shogunate has remained in power. In this reality, student councils are tasked with oppressing schools. Yagyuu Muneakira is a high school student who rebels against his student council with the help of girls who've had the names of famous samurai heroes passed on to them.

Narcotics Enforcement Agent Riko Ikazuchi is undercover with her junior colleague Noma in an apartment that serves as the hideout for a criminal organization. Despite Riko and Noma posing as a newlywed couple, the criminals begin to suspect them after not hearing any marital intimacy during the night. To convince them that they are a loving couple, Noma starts touching Riko's body...

Hiragi Utena is a major fangirl of the magical girls protecting her city and leaps at the chance to join their ranks. But once she transforms, she learns she's a villain who enjoys being a magical-girl-tormenting sadist instead!

Fourteen years after defeating the immortal warrior Himuro Genma and thwarting the Shogun of the Dark's evil plans, Kibagami Jubei continues to roam all over Japan as a masterless swordsman. During his journey, he meets Shigure, a priestess who has never seen the world outside her village. But when a group of demons destroys the village and kills everyone, Jubei becomes a prime target after acquiring the Dragon Jewel — a stone with an unknown origin. Meanwhile, Shigure — along with the monk Dakuan and a young thief named Tsubute — travels to the village of Yagyu. And with two demon clans now hunting down Shigure, Dakuan must once again acquire the services of Jubei to protect the Priestess of Light.

Awakening her dormant abilities as a devil one day, Yuuko Yoshida aka Shadow Mistress Yuuko, is entrusted with the mission to defeat the Light clan's shrine maiden, a magical girl, by her ancestor Lilith. Yuuko meets magical girl Momo Chiyoda through her classmate Anri Sada, and challenges her to a duel, but loses quickly due to her lack of strength. Since then, Yuuko has struggled with her role as a devil and her duel with Momo, and borrowed help from her regularly. However, by a strange coincidence, Yuuko also weakens Momo by taking away her power to cooperate in protecting the peace of Tama city.

When Mafuyu Oribe and her adopted sister Tomo rescue a strange wounded man, they have no idea what they’re getting involved with or what the consequences will be. Alexander Nikolaevith Hell is an Iron Qwaser, one of many opposing factions of super-warriors.

High school student Michio Kaga was wandering aimlessly through life and the Internet, when he finds himself transported from a shady website to a fantasy world — reborn as a strong man who can use "cheat" powers. He uses his powers to become an adventurer, earn money, and get the right to claim girls that have idol-level beauty to form his very own harem.

Sousuke Aikawa is a part-time worker who lives in a rundown apartment building where his only consolation is that the landlord is a beautiful woman and the girl who lives above him is cute. One day though, the ceiling above him creaks and... Bang! In from the second floor, directly above him, the cute girl comes crashing down on him…!? In an erotic encounter that can only be classified as a miracle, hearts and bodies are connected by chance. Then for some reason, he starts to live with both of these beautiful women!? Under this one roof, just what exactly will become of this crowded love triangle...!?