Sekirei

From wikipedia (probly not needed since i wrote alot of that on their site but w/e):

In Tokyo in the year 2020, Minato Sahashi has failed the college entrance exam twice, is awkward around women, and unemployed. Growing up, he could never stand up to his mother or little sister, a trend that continues to this day. In reality, Minato is extremely intelligent, yet his inability to cope under pressure results in his constant failure. As a result he has been branded an idiot and loser by many. One day, Minato meets a girl named Musubi, who literally falls from the sky. Minato soon learns that she is one of 'Sekirei' and he is her 'Ashikabi', human with special genes that allows them to "wing" (ie. form a contract with) Sekirei. This binds the Sekirei to him and allows them to use their full power in the elimination battle with other Sekirei. Made up of lolitas, sexy women, and bishōnen, the Sekirei fight in a dangerous and sometimes deadly competition (also known as "The Game" or "Sekirei plan") organized by Minaka Hiroto, chairman and founder of the mysterious and powerful MBI Corporation. Minato soon learns that being the partner of a beautiful girl is not all fun and games, especially when he discovers that an Ashikabi can have more than one Sekirei partner - and that's where the real trouble starts.

Sekirei
The Sekirei are extraterrestrial super-powered beings with genetic code similar to humans. The Sekirei spaceship had crashed at Earth and had been found in 1999 by students Minaka Hiroto (future MBI chairman, and total whackjob) and Takami Sahashi (future MBI head researcher and Minato's demon mother). Onboard this pair had found 108 life-forms (described as "One pillar and 107 baby birds").

The first of them (a pillar, shown as #00, possibly later renumbered and known as #01) was an adult.
Eight (later known as #02-06, 08-09, eighth of them is #01 or unnamed #07) were embryos.
99 others (later known as #10-108) were fertilized eggs.
The adult and eight embryos are also known as the Single Numbers. It is hinted, that unwinged Single Numbers are equal or even more powerful than winged others. All Sekirei had undergone adjustments for "Sekirei Plan", especially the Single Numbers (some of their adjustments were mischievous). Adjustments had been undergone not only for making Sekirei stronger, but also for controlling and stabilization of their power.

Also 8 mysterious artifacts (named Jinki (神器?, literally means "God vessel")[5] and numbered from #1 to #8) were found on Sekirei spaceship. If all eight of them will be gathered together, it will be possible to turn off all Sekirei. Sekirei under the same Ashikabi can merge their techniques.

Ashikabi
Ashikabi are humans with unique genes that enable them to empower Sekirei destined to serve them through an exchange of saliva between Sekirei and its Ashikabi, which is usually done through a kiss, thereby resulting in a "winged" Sekirei. Unlike Sekirei, who are mostly buxom women, or handsome young men, Ashikabi can be quite innocuous as they can appear in any gender, age, and even status. In the series, the power of an Ashikabi can be determined not only by the number of the Sekirei he or she has in his or her disposal, but by the bond between them. Four Ashikabi in particular, including Minato, are considered the most powerful ones having titles based on their names followed by what part of the city they rule over. In any case an Ashikabi dies, all Sekirei winged by him or her will also perish

Game
First stage: Sekirei are freed and must find their Ashikabi for winging. This stage ended when 90% of the Sekirei had been winged.
Second stage: Tokyo becomes a closed city. No Sekirei and Ashikabi can leave. The Ashikabi must wing the remaining unwinged Sekirei.
Third stage: The series of matches between Ashikabi. A prize for the winner of the match is one of the Jinki. Three teams (Ashikabi and up to three Sekirei) participate in the first and the third (current) match. Five pairs (Ashikabi and one Sekirei) participate in the second match.