Despite being a concept car, the Setsuna offers basic vehicular performance and is able to drive, turn, and stop. In order to achieve this, each type of wood, including wood selected for use in component, was selected for a specific application.
For the exterior panels, Japanese cedar was selected for the vividness and refinement of its wood grain and its flexibility as a material. For the frame, Japanese birch was selected for its strong rigidity. For the floor, Japanese zelkova was selected for its strength and excellent durability, and for the seats, the smooth-textured castor aralia was selected.
Traditional Japanese techniques such as okuriari and kusabi were used so that the wood could be joined without nails or screws. Okuriari, which allows the exterior panels to be fitted and taken off without using any nails, not only increases the strength of joints but also makes it possible to make partial changes to dovetailing and mortise joints if the fastenings have worn down.
This detailed care applied to the making of the Setsuna through wood-only joining techniques is an important facet of its unique personality.
The Setsuna’s body is composed of 86 handmade panels. Considerable thought was given to the design and creation of each panel from the outset, and each of these panels will develop and change differently as the car ages. Eventually, when repairs become necessary, individual panels can be replaced rather than needing to replace the entire body.
Looking at a panel that has been repaired, owners will be able to see the traces of where work has been done by hand, and sense the memories that have been passed down.
The lacquer finish used on parts of the vehicle has been carefully applied by hand. To bring out the grain of the wood, wipe-lacquering has been used for the door mirrors, seats, steering wheel, and body banding lines. Rather than normal lacquer, which is applied in layers, this method involves repeatedly applying lacquer to the surface and wiping it to set the lacquer along the grain of the wood, creating a combined texture from the wood grain and the lacquer. The intensity and color will change with use over time, becoming even more beautiful and evoking a completely unique impression at different moments spread out in time.
The comfortable seats are designed to give the impression of being able to kindly welcome and embrace anybody, like a wooden park bench. The castor aralia timber of the seats has been lacquered and the parts that come into most contact with the body have been covered over with leather. The character and depth of the wood, lacquer, and leather in these two seats all evolve with time to gently embrace each member of a family.
Aluminum has been used in parts such as the wheel caps, the steering wheel, and the seat frames. This creates a beautiful contrast that is also in harmony with the Setsuna’s wooden parts. Like wood and leather, metal also changes in character over time, making it a material that can feel well-loved.
As the wooden materials slowly bend over time, the Setsuna’s body line takes on a more pronounced, beautiful curve, like a boat. When viewed from the front, a heptagonal shape can be seen, and when viewed from the sides or from above, the form can be interpreted as elliptical. With the car’s boat-like exterior, one might envision a family setting out on a trip to the ocean.
