Name that Root Veg

Ok then, here's a little research project for you: what are these?

They are labelled "Kogashira" in Japanese, and I have no idea what they are.

Answers on a postcard, or in the comments section. :-)

- EDIT -

Thank you for the feedback, both to Bibi and to mum no.2 and her extended network. I now have compete cooking instructions which I'll be giving a spin in the next couple of days. Will let you know how it goes!