I ain't buying it either, lel.
In my mind, picking any 1 girl will come off as darn right bizarre. Best ending is probably one in which Kogarashi doesn't really date anyone. They live in a world in which they get over their deranged obsessions with one guy, and move on with their lives.
If this isn't a dream sequence, it's one of a hell of a bizarre way to close up a series.
P.S: "Relationship trolling", heh, nice one BlackHole.