What Is Kaya? The Tree Behind the Finest Go and Shogi Boards, How Old It Must Be, and Why Shin-kaya Is a Different Wood

If you look at Japanese go boards (goban) or shogi boards (shogiban) for long, one word keeps coming up: kaya (榧). It is the wood at the top of every price list, and the reason two boards of the same size can differ in price many times over.

Before talking about boards, this page looks at the tree itself — what kaya is, why a board-grade tree has to be so old, and why some boards sold as “kaya” are a different wood entirely.

The tree

Kaya is the Japanese name for Torreya nucifera, an evergreen conifer in the yew family (Taxaceae). The basic facts, as given in the Japanese Wikipedia entry for カヤ:

Maekawa Kaya Goban-ten, a go board maker, describes genuine kaya (hon-kaya, 本榧) as wood that is dense and rich in natural oils, with a fine, lustrous surface and a clear grain.

Why a board needs a very old tree

A one-piece board with legs is a thick, wide block cut from a single log. Only a large trunk can give that. Sources differ on the numbers:

• Kuroki Goishi-ten (a go stone and board maker): a legged one-piece go or shogi board needs a large tree roughly 200 to 800 years old.
• Maekawa Kaya Goban-ten: wood with a fine, tightly packed grain comes only from large trees 300 to 400 years old or more.
• Japanese Wikipedia (Kaya): a tree of 200 to 800 years is cited as a condition for the finest go boards.

The figures vary, but they agree on the point that matters: a thick one-piece board can only come from a tree that has grown for centuries.

An old tree is not automatically a good board, though. A board also needs few cracks and knots and an even grain. How the grain on a board’s faces is read — straight grain (masame) versus flat grain (itame) — is explained in Reading the Wood Grain of a Go Board.

Why Hyuga kaya ranks highest

Within kaya, wood from southern Kyushu — Miyazaki Prefecture, historically called Hyuga — is ranked highest. Japanese Wikipedia notes that straight-grained boards of kaya from Miyazaki are the most prized and the most expensive.

Kuroki Goishi-ten gives this order of board woods by price:

Hyuga kaya (southern Kyushu) > Japanese kaya > Chinese kaya > hiba > katsura, ginkgo, shin-kaya and similar > other woods

“Shin-kaya” is not kaya

The name most easily confused with kaya is shin-kaya (新榧, literally “new kaya”). According to Maekawa Kaya Goban-ten, shin-kaya is a different wood altogether: spruce imported mainly from North America. Because spruce grows into large trees, straight-grain boards are easy to cut from it; the wood is whitish (boards are usually stained), and its service life is said to be shorter.

Kuroki Goishi-ten describes the playing feel of shin-kaya as not inferior to genuine kaya, and the wood as resistant to warping and cracking — but it also says shin-kaya changes colour more with age and has a shorter service life. If you see “kaya” in a listing, check whether it says hon-kaya (genuine kaya) or shin-kaya.

The nuts, and uses beyond boards

Kaya is not only timber. Its seeds — kaya nuts — have long been used as well. According to Japanese Wikipedia, they are eaten after roasting, pressed for cooking oil and lamp oil, and used in traditional Chinese medicine.

Looking after a kaya board

Kaya resists moisture, but once it is a board it is treated as a natural-wood object. Maekawa Kaya Goban-ten’s basic care advice:

• Wipe it gently with a soft, lint-free cloth such as cotton, dry.
• Never wipe a natural-wood board with a wet cloth.
• Avoid direct sunlight, places near heaters or air conditioning, and places where wind blows straight through — these cause cracking, warping and sun fading.
• Very humid places cause mould and stains, so do not shut the board away where moisture collects.
• Keep a genuine-kaya board under a paulownia (kiri) cover or in its box, to protect it from dust and knocks and to soften changes in humidity.

The full routine is in Caring for a Go Board. If you are considering an older board, Buying a Used Go Board explains what to look at.

Summary

• Kaya (Torreya nucifera) is an evergreen conifer of the yew family, up to about 25 m tall, with yellowish-brown heartwood.
• It resists moisture and is regarded as the finest wood for go and shogi boards.
• A thick one-piece board comes only from a tree several centuries old (sources give 200–800 years, or 300–400 years or more).
• Hyuga kaya from Miyazaki ranks highest. Shin-kaya is a different wood — North American spruce.
• Kaya nuts have been used as food, oil and medicine.
• A kaya board is wiped dry and kept away from sun, heaters and air-conditioning, and draughts.

Checked 2026-10-11 for the Japanese edition. Sources: Japanese Wikipedia, “カヤ” and “碁盤”; Maekawa Kaya Goban-ten (board woods, care); Kuroki Goishi-ten, “About go boards” (all in Japanese). Tree ages differ between sources, so the ranges are given as stated.