Themed Harem

A type of Author Appeal in the Harem Genre. Like a particular Moe Moe character type? There's not just one character that fits in this show/game/what have you, but the whole cast is composed of them! (Well, usually. Sometimes there's an odd haremette out, just for variety's sake.)

Necessarily needs something like Four-Girl Ensemble or Four-Temperament Ensemble to differentiate their personalities, if not attaching other moe stereotypes to each of the characters, because you can't very well have four or five pining childhood friends that have been waking you up in the morning for fifteen years without a bit of variety between them.

Also, doesn't seem to apply to settings; even though these are actual and well-known moe zokusei, "they're all soldiers" or "they're all schoolgirls" doesn't count, or we'd have every harem series on here and then some. Plus it's really about personality type. If they were all the hardened soldier type with a secret Bodyguard Crush or tall high-school students with inferiority complexes, now that would be different.

Examples:

Originally Eroge and Visual Novels

 * Kanon has four childhood friends; in fact, the fact that Shiori is a standard Ill Girl with no connection to the hero (making her the odd haremette out) may explain why she always gets shafted in adaptations and merchandise. In this case, Nayuki has the traits of the typical Unlucky Childhood Friend, living with the male hero, harbouring a crush on him for years, and losing out.
 * The eroge Little My Maid is Exactly What It Says On the Tin: a Meido-centric game (although you could also go after the Ojou).
 * Speaking of trashy Porn Without Plot eroge, Secret Wives Club had Christmas Cake.
 * Lets Meow Meow has catgirls, a rabbit girl, a couple of dog-girls, and a Childhood Friend who doesn't mind dressing up like a Cute Monster Girl from time to time.
 * Futakoi, at the very least, had six sets of twins for the harem. It really took things to the next level and, naturally, repeatedly pushes the protagonist into some sort of awed dizziness (that is, when he's not too busy running from his harem's own "harems" or other "defenders").
 * Sister Princess is Brother-Sister Incest-happy, with 12 or 13 sisters running around proclaiming their Big Brother Attractions. In the game, the legal ones all have optional endings where they turn out to be Not Blood Siblings, and in the anime,.
 * Higurashi no Naku Koro Ni plays with the trope a little: it only looks like a harem series until people start dying, but it's not until that point that it becomes clear that the "harem" has a Yandere/Cute and Psycho theme.
 * The Visual Novel Katawa Shoujo is set in a school for special needs students, and so all the girls are somehow disabled, ill, or otherwise physically "vulnerable": you get to choose between one who is deaf-mute, one who is blind, one with no arms, one with no legs, and one who is covered in horrible burn scars.
 * Dracu-Riot is about vampire girls, with one exception for variety.

Other

 * Ranma One Half features dangerous martial artists of some kind or another, however bizarre or outlandish. They're all Tsundere Clingy Jealous Girls, on top of that.
 * Sayonara Zetsubou Sensei may count - the protagonist is male, and most of the other characters are female students. Many of them have crushes on or Ship Tease with him, and every single one of them has an unnerving psychosis of some kind. Some of them have actual psychological disorders, others are just plain weird.
 * G-On Riders had nothing but Meganekko.
 * Minor joke in Black Lagoon fandom, as in so far, Rock, of all people, attracted at least two Action Girls (Revy & Eda) and one Lady of War (Balalaika). Although it's definitely obvious that only one of them is clearly falling/lusting after him (in a way), at least they had some potential.
 * The girls in Kaibutsu Oujo are all dominant/assertive, with half being Tall, Dark and Bishoujo.
 * Rosario to Vampire - an Unwanted Harem consisting of five Cute Monster Girls.
 * Guardian Hearts - a harem of Magical Girls.
 * Tenchi Muyo - a harem of Human Aliens.
 * Hanaukyo Maid Tai - a harem of maids.
 * Hand Maid May - a harem of Robot Maids.
 * El Goonish Shive had it Played for Laughs once (for ).
 * While it might not have been on purpose, Denpa Onna is basically a harem of weird girls.
 * The webcomic Ow My Sanity - a harem of Eldritch Abominations who take the form of Cute Monster Girls.