I didn't find the way to add a tag but the artist is Zundare Pon, for sure.

obutudan said:
I didn't find the way to add a tag but the artist is Zundare Pon, for sure.

If you'll notice, right below the image are the links "Edit" and "Respond." If you click on "Edit," it will allow you to edit the data associated with the image - including the tags. So, you enter the tags in the box labeled "Tags" (note that all tags use underscores instead of spaces) and click on "Save Changes," and the page should reload with the changes that you made. Click on "Respond" to show the comments again.

Ok, I got it: I have NoScript on Firefox, so that's why 'edit' didn't work with me...

My bad.