Both series revolve around a love triangle in which two girls have the same name, but have completely different personality. Honeymoon Salad is tad more serious and mature, while Kirara is more on the comedy side (and has more fanservice). Neither of the seires is really good, but if you thought one was ok, you'll probably won't have issues with the other one.
This is another one of those gut feel recommendations. Sure both series are seinen that feature a love triangle and both have mature content at times, but that would probably not suffice on it's own. There seems to be a familiar feel about those two (especially in the later volumes), but I can't quite name it. So if you liked one, you'll probably like the other one as well.