Soukou no Strain

I've started watching this series recently. It's yet another mech drama, with little to differentiate it from other such shows, yet for some reason I really like it.

In this universe, the struggle is between the Union and the Deague, two groups that fell into conflict as humanity expanded into space. The Union fight with Gambees, which are piloted humanoid form robots, as well as with Strain, an advanced piloted robot which is apparently primarily controlled telepathicly. A Strain can only be piloted by a Reasoner, which is a person from which brain cells were extracted before birth to create an interface, their Mimic. The Deague fight with Tumors, which are small automated leach form bots with strong manipulator arms as well as an oft-used explosive self-destruct.

The story starts with Sara Werec saying goodbye to her brother, Ralph Werec, a top-ranked Strain pilot who is leaving to fight the Deague. In order to be able to be close to her brother, Sara puts her full effort into training as a Reasoner. One night, the Deague attacks the academy Sara is training at, and the usual Tumors are accompanied by a mysterious Strain. Sara fights this Strain only to be defeated; injured and her Mimic destroied, Sara escapes the wreckage of her Strain to find the mysterious Strain landed by an old research facility. She goes to investigate, to find the pilot, her brother, carrying a strange girl out of the facility and into his Strain. Despite Sara's pleading, Ralph doesn't say a word and simply leaves. So begins Sara's life as a Gambee pilot, still strugling to be able to get close to her brother, but now for a different reason.