The lengths of kumiko are at last joined into a lattice of triangles. The aim now is to fill in each of the triangles with smaller pieces of cedar to form the sakura—or cherry blossom—pattern.
The first pieces to go in form the center of the blossoms. Using a chisel and a small paring guide, the end of a length of cedar is pared away to a precise angle, the final length is marked, the piece is sawed, and the second end is pared to achieve the final length and a smooth finish. These tiny lengths are then pressed into the corners of each triangle.
To lend the grid a crisp, finished look, a slightly thicker frame, also made from yellow cedar, is added. In order for the grid to fit into a square frame, the excess length on each kumiko strip must be removed. This is done by carefully sawing through the midpoint of the outer joints, taking care to make a square cut.
Once the grid has square corners and the frame pieces have been joined and their edges chamfered, the entire assembly is brought together:
This is where the magic happens.
The petals of the cherry blossoms—ultimately appearing like three spokes inside each triangle—are formed from two thin pieces of cedar. The first piece makes up two of three spokes, and therefore must be cut and hinged open to allow its two halves to be set at an angle to one another.
To accomplish this, a small length is squared at both ends, marked at its center, and then carefully sawn across its face until only the faintest whisper of wood remains on the opposite face. The goal is to leave as many wood fibers as needed to keep the piece intact, but so few that it may be gently bent open. When all goes well, sunlight glows through the hinge.
The second petal-forming piece is again a small length of cedar. One end is made square, and the other is cut to form a spear point that fits into the space created when the hinged piece is pried open.
To assemble the petals, the hinged piece is opened and placed into a triangle in the grid, care being taken to align and position its lengths evenly. The spear point piece is then pressed down until it is flush with the surface of the grid. The pressure of the pieces against each other holds them in place.
This is then repeated for every triangle.