Devadasy

20 years ago a mecha called Devadasy was discovered in Tibet, and the organization Spirits was created to study and repair it. In the present day, an alien invasion has begun and Spirits is now an organization that uses Devadasy to combat this threat. Two friends, Kei and Naoki, join Spirits to help save mankind and become Devadasy's pilots - but what secrets is Spirits hiding about the Devadasy, fellow pilot Amala, and most importantly, Kei himself?