De:vadasy (創世聖紀デヴァダシー, Sosei Seiki Devadashi) is a 2000 PC video game and anime OVA about a giant human-piloted robot.
[1] 425 days since enemy landing, pilot Kei Anno is deployed in a Devadasy to counter an alien nanomachine attack on a city, but he deviates from orders following a psychic signal.
However, the alien nanomachine mass reactivates her abandoned mecha, forcing them to launch the first with Kei and Amara together, and another female pilot, Naoki Matsudo, volunteers jealously to take her place.
Throughout the first episode, the story goes back to 53 days before, when Kei and his childhood friend Naoki are recruited by Misako Takashina for Spirits, an international organization that protects humanity through the use of Devadasy.
Twenty years before present time, an expedition led by Kei's grandfather is also shown to find a hibernating Amara in an ancient temple in Tibet, as well as the Devadasy and prophecies about the invasion.
Upon discovering this in the pilot school, and under effect of special drugs, Kei suffers headaches and altered behavior, even trying to rape Naoki, so Takashina seduces him to obtain his sperm, finding that Devadasy's nanomachines are affecting him.
Takashina and officer Yamada self-destroy the evacuated Spirits base, which interrupts the process, but the alien absorbs instead the explosion's energy and takes the physical form of a mecha, carrying a captured Naoki as its pilot.