Talking About... (2005)

Blurb:
Meet Sarah, successful event planner by day... frustrated 30 year-old virgin by night. Actually, she’s not quite 30 yet. The night before the dreaded birthday, she vows to do something about it. Meet Gang-E, a 29 year-old graphic novelist. She only has one problem... she likes them young. Males, that is... especially her 19 year-old assistant and lover (and adoring fan) Jooyoung. No more boys, she pledges. Gang-E vows to find a real man, even if it kills her. And finally, meet 27 year-old Amber who ruthlessly climbs the corporate ladder, leaving many dead career corpses in her wake. Amber has never met a man she didn’t like (and sleep with), nor has Amber ever met a woman she did. Three lonely women in search of "happily ever after" in one modern city filled to the brim with difficult men. We all yearn to drive down a straight, calm road leading us to our happiness. But if it were that easy, life wouldn’t be such an amazing ride.

Source: www.anisearch.com/manga/14629