Better bokeh ?

First all, bokeh is the term we use to describe the quality of the out of focus areas of an image. The out of focus areas are the areas which fall outside of the depth of field. Everything within the depth of field will be "acceptably" in focus. In the first picture you posted the subject being in focus with the background blurred. That is the result of a shallow depth of field (DoF). The subject is within the DoF while the background is outside of the DoF making it blurry. The bokeh is roundish and smooth.

DoF is dependent on 3 things: Aperture, Distance to subject, and focal length.

To make your DoF larger you can:

• Use a narrower aperture
• Get further back from your subject (increase the distance to your subject)
• Use a wider focal length

To make your Dof shallower you can:

• Use a wider aperture
• Get closer to your subject (decrease the distance to your subject)
• Use a longer focal length

What you specifically seem to want is a shallow DoF. So yes getting a lens with a wide aperture will help, but it isn't the whole story. So a 25mm f/1.7 might be helpful, but you may want something a little longer. I would take the other's advice and see what you can do with what you have for now.

A 25mm f1.7 would give you an equivalent image to a 50mm f3.5 roughly on a full frame camera. Usually to get out of focus areas like that, a 85 mm or even longer lens is used, between f1.4 to f1.8. This would mean you would likely need a longer focal length than 25mm and a larger aperture than f1.7 if you are trying to get a look like that. I believe there's a manual focus f0.95 lens for m43 that may be better.

Having said that, the subject to camera distance is very important - I can get a blurred background on an iPhone if I put the subject close enough to the lens