The reason this model is classified as intermediate is because of a closed sink at step 8. It's tricky to get it right, but with practice it comes easy.
You should wet-fold this model, foil nor kami will work. I used Canson mi-teintes paper to fold the model in the picture.
To get the body to not look like an upside down cup., you may have to crimp the tail before you have thinned it, depending on how you do step 10.