The Mars Canon (2002)

A look at the problems two couples, Kohei and Kinuko, and Manabe and Hijiri, have in their relationships, and the solutions they try to devise as a way out. Kohei and Kinuko, despite their age difference, seem like a happy pair, but their is an insurmountable distance between them. Kohei is married to another woman, and Kinuko, though she know he will never divorce, can't bring herself to break off the relationship and start anew. Manabe and Hijiri, meanwhile, start off happily enough, but eventually their passion begins to wane as Manabe starts looking to other women for sex. Hijiri, feeling rejected, moves into an apartment next door to Kinuko, where she plots to break up the mismatched couple to her own advantage.