This series followed "Les Filles d'à Côté" and "Les Nouvelles Filles d'à Côté". Thierry Redler(from these two series) is joined by Rochelle Redfield (from another J-L Azoulay sitcom for adolescents). There are many things in common between "L'un contre l'autre" ("The one against the other) and "Les Filles d'à Côté". In "Les filles..." Marc (Thierry) shared an apartment with an American photographer Daniel (Bradley Cole) who created advertisements. In "L'un..." Jean (Thierry Redler) is married to an American photographer Gin (Rochelle Redfield) and he works for an advertising agency.
In the three series we see Thierry going from playing an utter loser in "Les filles...", to becoming a success with the ladies in "Les nouvelles..." and in this series he is happily married but with similar contrived situations occurring.
In all three series some characters "talk to the camera" (to comment on the on-going situation) - there is quite a lot of this in "L'un..."
Again in all three series no-one ever smokes, but alcohol is consumed - at times excessively if necessary for the story line of the episode concerned.
Some of the "bit-players" from "Les filles..." and "Les nouvelles.." appear also in "L'un..." but as different characters, e.g. Laure Sabardin who changes character name, but keeps the same sort of job.
The syllable "Red" in both their names is highlighted in the opening (series) credits. Three colours are used with "RED" being in red (Thierry REDler, Rochelle REDfield)
