Also known as the "chokoku-to," the hangi-to is the basic Japanese woodblock carving tool, used to carve lines in the wood. It is the only asymmetrical tool in the set of Japanese woodblock tools. It has a tip and slanted edge--and there are right-handed and left-handed versions also.
The hangi-to in fact comes in a variety of different lengths, widths and blade angles depending on the sharpness and depth of the cut the carver wants.
Pronounced "ah ee soo kee," the name of the ai-suki translates literally to "the in-between becomes apparent." Ai-sukis are flat blades with a slightly rounded edge. Artists push ai-sukis into the the wood to clear away larger areas between lines carved with the hangi-to.
Most Japanese printmakers have a range of ai-sukis in varying widths, and use them all.
Artists use maru-nomis with hammers or mallets to clear away large areas of wood. Since woodblocks only print what is not cut away, heavy use of the maru-nomi is necessary for sparser and simpler compositions.