Red Dwarf (UK)

Kristine Kochanski was initially a Red Dwarf navigation officer whom Lister had a crush on (later retroactively altered to be his ex-girlfriend) and whose memory he had cherished ever since.

Later, the crew happen upon an alternative dimension, where Kochanski had survived the Red Dwarf cadmium II accident. She joined Lister and the crew after the link to her own dimension collapsed.

In Back to Earth, Lister believes her dead, it is revealed that Kryten, the sole witness to her "death", had lied to him. Kochanski had instead fled the ship in a Blue Midget when it became clear Lister's complete lack of self-respect and indulgence on excesses was slowly killing him, which greatly depressed her. Lister is advised by fans of the television series to find her in "the next series" and to make amends.