Alien from the Darkness

Alien from the Darkness (淫獣エイリアン) is a space hentai OVA, directed by Norio Takanami, that was released in 1996.

Characters
Hikari - Hikari is the main character of the movie. She is a Computer Expert for the Spaceship Muze. On a mission in space, her Crew discovers a lifeless vessel called zogne. Curious to see whats inside they gear up and board the ship.

Al - Al is the A.I. for the spaceship Muze.

Flair - Flair is found by the crew in a freeze chamber aboard the Zogne. She is the only survivor on the ship, as the rest of the passengers and crew have died mysteriously. She is treated by the crew of the Muze as a medical patient, although she cant remember what happened to her fellow passengers.

Plot
While on a government mission far from civilization, the all-female crew of the spaceship Muze finds a seemingly lifeless ship, named the Zogne, drifting in space. They investigate and stumble across numerous dead bodies as well as a single survivor — Flair, an innocuous-looking girl, who is diagnosed with amnesia after being found in a sleep chamber. The crew bring the girl back to the Muze and treat her with sympathy as a medical patient. Computer expert Hikari begins attempting to decrypt the computer records of the Zogne to find out what happened to its crew.

After further searching, Hikari discovers the illegal drug Metrogria (which disables the immune system) on the Zogne, and the Captain of the Muze commands that the Zogne be destroyed. Meanwhile, Flair (who is actually a dangerous tentacled alien) has begun to wreak havoc, approaching the crew members one by one and tentacle raping them to implant eggs in them. This causes the victims to become insane and die. Hikari finally learns this secret after decoding the computer records, but not before the Captain and several other crew members have already succumbed to Flair.

Hikari and her sister attempt to destroy Flair with weaponry, but the alien seems invincible. Eventually, the alien corners the sisters in the ship's cargo hold. Hikari escapes but her sister does not, ending up locked in the hold with the alien. Seeking revenge, Hikari puts a Metrogria capsule in a pistol, re-enters the hold and shoots the alien, mortally wounding it. She then opens the cargo bay door and the alien is blown out into space along with several dead bodies.

The show has a post-credits sequence where "the real ending" is revealed. which reveals Hikari's sister returning to the control room in a normal state to greet her, which Hikari embraces her. As they hug, her sister shows an evil grin with the film ending with Hikari's pet snarling. In a cut ending scene, it reveals that Hikari managed to kill her sister but causing her to have a minor nervous breakdown.