OPUS：龍脈常歌

Taking place in a lawless solar system at the height of a gold rush in space, players play as the exiled noble Jun, who is accompanied by Eda, a witch orphaned by war. Together, they embark on a journey of self-discovery, as they search for treasure-filled asteroids of legend and lore. However, what appears to be a blessed encounter will turn into a lifelong burden... Will Jun, now a withered old man, be able to see his lover one last time?

[From the official website]