Four wings in the coat

To Rabbi Michael, Shalom Rav,
I’ve been wearing a coat for a while now that has sharp corners and is open in the front (with buttons) and the collar goes up the neck with sharp corners facing up. I didn’t seriously think that maybe it needed a tassel.
It resembles a raincoat that goes down to the knees (or an ultra-Orthodox robe), except that at the top it has flares at right angles upwards, which can be buttoned so that they wrap around the neck, without a hat. Like a shirt collar that doesn’t fold down (although I can also fold it, but I don’t like it as much). It has a slit in the back.
It is made of fabric.
Is it considered a four-winged garment?
If so, what are the options? Should I simply tie tassels to it? Or can I also round it? (I actually like tying tassels) If I tie tassels, then tie them at the neck, and at the corners down the front? And what about the corners in the slit at the back?
Many thanks,
Ofir