Outlanders Vol 1

From the Dark Horse edition

A full-speed-ahead space opera filled with biomech warships, interstellar mayhem, and a beautiful (but deadly) alien Princess who's in love with an earthling. The action-packed story follows the relationship between earthling photographer Tetsuya and the headstrong alien princess Kahm as it threatens to lead to galaxy-wide war! With its emotional impact and huge cast of wonderful characters, this massive, sprawling epic has been a huge fan-favorite for more than ten years.

Source: Anime News Network Encyclopedia