@Tanterei
Well, on reflection it's been in hiatus for the last 7 years, so more "unconcluded" than "running"... And the mangaka is now 69 so there's little chance of her ever finishing the story, even though she said on Twitter a couple of years ago that she was going to. But she also promised in 2000 or so that the story was nearing its end (reason for me picking it up), so make of that what you will...
Still worth reading IMO, even though the most recent volumes give a slightly surreal impression against the 70s ambience of the first 40 volumes or so. Only about 5-6 years have passed in the story, but suddenly there are cellphones and whatnot, which would have prevented a major plot point. Sadly the English scanslations are kinda behind, in my language there's an official release that's current, so stuck at volume 49 just like in Japan.