A 1975 SciFi {{Shoujo}} Manga originally written by Creator/MotoHagio, with an anime adaptation released in 1986.

It is the future. Earth, now known as Terra, has made contact with various other planetary civilizations, and formulated one central school for the cream of the crop. Beings from around the known universe gather to take the entry examination; the test is hard, but it's said that admission guarantees an influential position after graduation, and the riches of the universe are theirs for the taking. Ten young space cadets are put onto a decommissioned spaceship in orbit around a small star as the final part of the test.Their orders are simply to survive as long as they can with what they have. There is an emergency beacon that they can activate to be rescued, but the implications for their score on the exam are obvious. However, once they arrive at the decommissioned ship, [[TrainingAccident they find that their crew has mysteriously gained an eleventh member. And then things start going wrong]]...

As the days pass, the eleven cadets, each from different cultures, species, and walks of life, must deal with their suspicions of each other as well as the sudden knowledge that the orbit of the spaceship is gradually decaying, rising the on-board temperature as it gets closer and closer to the star. With this rise in temperature, a mysterious sickness begins to spread among the crew as they work to stabilize their orbit and determine who among them is the spy.

!!''They Were Eleven'' shows examples of the following tropes:

* AccentAdaptation: Frol's coarse and straightforward method o' speakin' is translated in the dub as a Dixie accent.
* YouFailPhysicsForever: Orbits about a single star (or other massive object) don't decay, except possibly unnoticeably slowly (as on the order of centimeters per million years -- except for binary neutron stars).
** Those ''[[FanWank could]]'' be some '''really''' powerful ExplosionPropulsion, InertialDamping and construction materials.
** Or [[spoiler: All part of the SecretTestOfCharacter]]
** No, but the ship coulb be 'knocked' from a round orbit to an elliptic one due to speed loss (caused by a leak maybe?) . Although the presence of the planet should attract the ship instead, unless the ship is on the edge of the gravitational influence of the planet vs. The blue star...
* {{Bokukko}}: Even though Frol considers himself a man, he generally comes across as one of these.
* FriendOrIdolDecision: [[spoiler: Frol catches the sickness after the students save the ship. Despite Frol's desperate pleas, everyone else agrees to activate the beacon, sacrificing the test and their own dreams to save his life.]]
* {{Hermaphrodite}}: Frol -- his species is asexual until adulthood, when gender is determined; traditionally, only the firstborn of a family is made male, and the others female. However, someone who was admitted into the Cosmo Academy can pick their own gender, and that's why he's here. Knu delivers the exposition because his species is similar.
* ILied: [[spoiler: The BigRedButton is supposedly a full forfeit, and will cause everyone to fail the exam. In reality it's fully expected for the test-takers to press the button; they are actually graded on how long it takes them to reach that point, and how they dealt with each crisis that evolve.]]
* NoExportForYou: The DarkerAndEdgier one-volume sequel manga (''Zoku 11 nin Iru! - Higashi no Chihei Nishi no Towa'', "Eastern Horizon, Western Eternity,") has never been officially or unofficially translated into English.
* SamusIsAGirl: Played with. The other students react this way the first time they see Frol out of his spacesuit, until he corrects them. Later, when another student sees Frol in the shower and notices that he's missing something important, most of the other students conclude that Frol's pulling a SweetPollyOliver until Knu makes TheReveal.
* SecretTestOfCharacter: [[spoiler:Beside the obvious test of ingenuity and survival skills, the exam tests how well would-be students can handle pressure with no outside support. The eleventh examinee/supervisor throws everything off-balance right away, and performs sabotage throughout to pressure the team to press the button. Of course some of the things that go haywire weren't part of the test but the cadets get extra points for those.]]
* TenLittleMurderVictims: [[spoiler:Subverted. No one ends up dying.]]
* TrainingAccident: The vine-sickness was not part of the test. It only happened because one of the explosive charges the crew had to disable at the beginning of the test went off and knocked the ship out of orbit; it then got close enough to the system's sun for the vines to start growing again.
* "WhereAreTheyNow?": In the anime movie adaptation, done in the style made iconic by AmericanGraffiti.