5"7 weigh 150 mostly wear medium and im skinny fat what size should i get ?

It's a relatively loose fitting 3/4 sleeve garment in the style of older Japanese house coats, so particulars of size shouldn't be too big of an issue as clothing of this style typically masked body shape anyway unless you have a large beer belly. I'm about 6ft 170lbs with broad shoulders and I'm wearing an M with the sleeves being a bit closer to half sleeves and the length fitting like a normal shirt, so for someone your height and build, you might have more of the authentic fitting. I like it a little tighter because I wear it around the house to keep me just the right temperature, but give me the air flow and flexibility to do things like wash my hands or wash dishes without getting wet sleeves. Looser probably looks better than tighter with something of this style though. Unlike a lot of clothes you see modeled on Amazon, the pics with the models are very much how they will look. I believe it did shrink a bit in the wash, so that is something to consider too.

We i big men in the usa. you have a good product but the sizes are very small for us in the usa 3x 4x will be much better for us.

Yes, It's really a beautiful cardigan and we will develop more size in future.

Why does the ad state that it should be hand washed only?

This fabric is a cotton-linen blend, and if you wash it in anything other than cold water, it will, like all linen, shrink to a handkerchief. It is a soft fabric that should be treated like a delicate garment, so hand washing when needed, in only cold water, will prevent it from fading and keep it looking like new for years to come. And, you will love both the look and feel of this kimono jacket once you put it on. A washing machine will eventually tear this jacket and fade the black. Hand washing is easy and quick. Hope this helps.

Should this item be washed or dry cleaned?

It can be washed in a clothes washer. Since the material is made from linen fabric, it should be washed by itself or similar materials and then dried on low heat, gentle cycle if available on your dryer or just air dry in a well-ventilated area.