I was looking at the latest aatp's release and I noticed that the straps on the jsk are pretty thin. Maybe this is common and just haven't noticed? For some reason I always thought that jsk straps tended to be thicker. 

Anyway, I wondering if you can wear a lolita blouse under this kind of jsk or is it meant to only be work with a bolero/cardigan?

I have some dresses at home with straps like this and pretty full skirts and I kept thinking they would be great for lolita coords, if not for the thin straps.  I usually wore them with a bolero/cardigan, but it might be nice to mix it up a bit :) 

you can wear it how you like

you most certainly can! and i hope to see it if you do buy it hehe

I think they look just fine with blouses. It's similar to wearing a strapless JSK with a blouse

Wow~ I didn't even know there were strapless jsk! 

yup, I have one from bodyline. AP released a strapless JSK recently too.

Oh~ how does it stay up? Is it very snug like a tube top?

It might look nice with a blouse underneath, but you'd have to experiment to know for sure. There's no official rule or anything. At any rate, it will still look beautiful with or without one.

I think it would be adorble with a blouse. Try it. Experiment.

I also have idea straps should be wider. But I often wear blouse together, so it's ok for me.

they don't stay up lol XD

In my strapless JSK there's corset lacing that you have to tie verry tightly if you don't want it to fall down.