Knickerhawk just gave a very good answer.
Buy a sigma 85mm f1.4 in the Canon mount plus a spedbooster.
The OP did specify "MFT lenses."
Setting that aside, knickerhawk's speedbooster suggestion might get the job done in the case of a fairly static portrait like this. What about subjects in motion, though? How well does the AF work? Is C-AF available?
I do think the dreamy bokeh has some impact on the "look" of the shot under consideration. The 135/2 portrait lenses are famous for this, and it's unclear whether the Sigma combo would have the same impact. I believe knickerhawk had suggested the Canon 85mm f/1.4 and 85/1.2, however, and I assume those have nice bokeh.
Ultimately, though, while adapted lenses may be a nice option for dual-format shooters who already have the lenses, how many other people are going to go out and buy a $1,600-2,000 Canon lens plus speedbooster just so they can stick it on a m4/3 body?
Once the conversation gets to that point, I don't think it's out of line to suggest looking into a 5D or D700 and a $900 135/2 instead.
However this type of separation isn't difficult with the vl 42.5mm f0.95,
The perspective and DOF would both be different. As I said in my other post, it *might* not matter so much in this particular photo, but there are other cases where you would not want to mess with these elements.
If you were to suggest to a m4/3 user that they should sell their 45/1.2 because they already have the 75/1.8 (or vice versa) and the two lenses are close enough, I doubt they would be convinced.
nor difficult to achieve when you have a subject willing to pose.
Personally, I sometimes use the 135/2 on FF to photograph my running whippets, as I'm often shooting in close quarters against ugly urban backgrounds. I would not like to do this with manual focus, but it might work for some people.
With some planning and understanding of the lens, the 75 mm f1.8 would look very good as well as we can get physically closer due to the 4/3 ratio. This would help separation as well as simply bringing your subject farther from the background.
But then when you do some vertical shots, the tables are turned.
Anyway, if I could no longer shoot FF and wanted to do this kind of shot on m4/3, I imagine I would happily use the 75/1.8. It's a very nice lens. It would depend mostly on the AF, I guess.
Here is how I see it, if you have to ask if a lens is what makes that shot look good you have ignored all the effort the photographer put in selecting the location and the light, time if day, time of year etc. Styling the subject, post processing etc.
I don't see it as an either-or thing, and I don't see the problem with asking about gear on a gear forum. It's a fact that a 135/2 on FF does produce a distinctive look (hence all the posts suggesting the shot in the OP must have been done with software or filters), and a lot of people like that look and want to know how to get it.
If someone doesn't care about lighting or location to begin with, remaining in the dark about lens choices is not going to change that.
One stop of aperture size will have almost no impact compared to all those other variables.
Clearly something is making an impact, or we wouldn't have all these people insisting the shot can't be done without some kind of trickery.
Again, the disclaimer: I'm not saying that beautiful portraiture or blurred backgrounds can't be achieved with m4/3. I joined the thread for two reasons: 1) nobody had yet made the connection with physical aperture and background blur, which I wrote about in my first post and 2) I saw some irony in the fact that people are always posting that you can get close enough to the "FF look" with MFT gear and a little knowledge and skill, yet apparently a 135/2 or 85/1.4 on FF produces effects so exotic that you get a bunch of people insisting that software or filters must have been involved.
Julie