Here are some answers to frequently asked questions about the Hobonichi Techo.
Can I purchase the Hobonichi Store exclusive pen?
The bonus pen included with Hobonichi Store purchases is not available for individual sale.
However, the closest commercially available model is the uni (Mitsubishi Pencil) JETSTREAM, product number SXE3-400-05. While the design differs slightly from the Hobonichi bonus version, you can find this pen at most stationery stores.