Queen's Blade is a series originating from Japan that is a perfect representation of how /d/ and /tg/ can get intermixed. The setting/series began its life as a Japanese spin-off to the Lost Worlds, an Old School Roleplaying game revolving around the use of "visual combat" gamebooks to depict battle between selected fighters. Queen's Blade took this basic idea and gave it an ecchi slant, creating a slew of characters who were all sexy women, and even a few monstergirls, but still using the basic game mechanics.
This being released in Japan, it took off, and eventually inspired a series of novels, anime (serial and OVAs), manga and videogames.
Being basically somebody's magical realm writ large, it's not hugely complicated to get the basic gist of it: the Queen's Blade setting takes place in an Amazon-themed world, where ruling is taken care of by powerful female warriors. Every four years, a grand tournament is held in which any warrior-women who wants to enter can compete; last woman standing gets to be queen of the world until somebody manages to kick her off the throne in a subsequent tournament.
There's more background to it - for example, the world used to be run by a conventional aristocracy, but they got themselves into a war so big and destructive that the gods themselves came down from heaven, slapped the shit out of them, and set up the Queen's Blade tournament that has ruled ever since - but the above paragraph is all you need to know going in.
One notable aspect is that the series is very much an ecchi shonen slant on the Sword & Sorcery style; as such, magic is portrayed as evil, with "real" fighters instead relying on semi-mystical fighting techniques and magical weapons instead.
...Where do we even start? This series is crawling with girls from different story arcs and continuities, ranging from the fairly ordinary every-girl protagonist to lesbian elf mercenaries who wear trained snakes in lieu of panties to slimegirls who disguise themselves as pink bunnygirls to perverted angels.
Let's take it from the top, then...
Leina Vance: Middle daughter of the Vance family, who used to rule the world before the gods slapped them off of the throne and instituted the Queen's Blade program. Ran away from home hoping to become a strong warrior. Protagonist of the anime, mascot of the franchise as a whole. In the Hide & Seek manga continuity, she's not only aware of her sisters' incestuous desire for each other, but wishes they would actually get together.l
Claudette Vance: Eldest of the three Vance sisters, the problem is that she's Count Vance's bastard daughter and so prohibited from inheriting any sort of power. She wants daddy's love, but he treats her like shit, perhaps because she's the strongest of his daughters despite being illegitimate. She has incestuous lesbian desires for her youngest sister, Elina, which are more prominent in the manga "Hide & Seek".
Elina Vance: Youngest of the three Vance sisters, a sadistic, incestuous, lesbian who serves their father as an assassin. She wants to fuck both her sisters. Is human, but has a catgirl motif.
Nanael: A mischievous, lusty, arrogant angel disliked by others for both her trouble-making ways and her deformity of having assymetrically sized wings. Heaven ultimate tries to get her out of the way by sending her to Earth with orders to partake in the Queen's Blade tournament (which she mostly sees as an excuse to chase after handsome guys) and attempting to handicap her by demanding she carry & not spill a bottle of "Holy Milk".
Melpha: The "healslut" meme incarnate, this priestess from the capital city of Gainos is known for two things; her fuck-off-huge boobs and her use of "Holy Poses" as a combat mechanic, basically unleashing divine magic spells through sexually provocative stances and actions.
Tomoe: A female samurai-miko from the island nation of Hinamoto. Dresses quite sensibly (by this series' standards), and is incredibly pissed off by just how slutty everybody in the mainland seems to be, finding great offense in the skimpy clothes and sexual antics she's constantly surrounded by.
Shizuka: A rogue ninja who is Tomoe's best friend, despite being a busty girl who likes wearing skimpy clothes. She ends up getting herself killed in order to motivate Tomoe to fight harder in the tournament.
Melona: A slimegirl who takes the form of a pink-haired bunnygirl. Speciality attack is squeezing her huge tits in order to spray gouts of corrosive slime at her foes from afar. She works as a spy and assassin for the Swamp Witch, the closest thing this setting has to a BBEG, which is somewhat undermined by her being a huge attention whore.
Menace: A "mummy" who takes the form of a near-naked sexy girl. Originally the decadently hedonistic and self-centered lesbian queen of the lost kingdom of Amara, she was betrayed by her favored concubine, who worked with an outside force to topple her kingdom before throwing her into the palace's slave-pens, where she was beaten & raped to death. Revived by the Swamp Witch as a minion, she refuses to serve her, instead trying to rebuild Amara and pursue an unlife of eternal carnal bliss.
Nowa: A perky, skimpily clad half-elf who refuses to let the contempt she is regarded with by most of the pure-blooded elves get her down. Decided to enter the Queen's Blade tournament just for kicks.
Alleyne: An elven combat instructor and veteran warrior.
Echidna: An elven mercenary, infamous for being one of the biggest perverts in the entire setting; it's not just that she's a shameless lesbian pervert, but she runs around completely bottomless, save for a trained snake that she wears coiled around her privates like panties. She's even been known to use this snake to rape other women.
Branwen: The sub to the Echidna's dom attitude. A slave warrior woman who is made by the infamously talented hentai artist Oda Non (master of MILFs). Basically a mid 30's woman who is the slave of a goblin and fights for her eventual freedom counted in chainlinks on her leg tattoo, tortured with electricity and whips in off time. Don't worry, she loves every minute of it.
Queen Aldra: A youthful seeming (but not loli) half-demon with a petrifying gaze attack, the current bearer of the title of Queen.
Irma: The scantily-clad head of Queen Aldra's secret police. Really hates Echidna, her former tutor and first lover, for just walking out on her without a word.
Cattleya: Perhaps the most infamous member of the Queen's Blade cast; an Amazonian MILF with both rippling arms and the biggest tits 'n' ass in the series. A weaponsmith by trade, she joined the tournament to search for her missing husband Owen. Carries a "Giant-Killer" greatsword that Guts would find admirable.
Risty: A busty redhead female bandit who robs from the rich to help the poor. Has an infamous first appearance in the pilot episode where she expertly ties Leina and brings as captive, parading her naked through towns they travel to sell her back to her sister.
Nyx: A peasant girl who once worked for Elina Vance. The experience drove her so insane with the need for vengeance upon her abusive mistress that she willingly partnered up with the sapient, perverted magical staff Funikura, which powers itself up by raping her with tentacles, so she could use its magic to destroy Elina.
Where To Start
Mangaboos can just start with the manga of that name. For anime, it's "Rurō no Senshi" = "Exiled Warrior" for subs and "Exiled Virgin" for dubs.
Queen's Gate crossover aka the version with characters you actually want to play
This is the only reason anyone who isn't a otaku/weeb would even play Queen's Blade. As it has game books allowing players to use female characters from various video games and other franchises. Though some are nerfed compared to their canon counterparts. As the likes of Dizzy or Noel with access to their full power would solo just about any scenario on their own. Seriously, none of the cast of Queen's Blade would actually stand anywhere near a 1% of a chance of winning when pitted against the likes of Kasumi, Ivy Valentine or Mai Shiranui. It wouldn't even be rape, just a brutal old school curb stomp.