Eboya Natsume Kogetsu Yellow Small Fountain Pen

Eboya Natsume Kogetsu Yellow Small Fountain Pen

Eboya is the last factory devoted to ebonite production in Japan. Every pen reflects a commitment to traditional craftsmanship and continuous innovation. Ebonite —one of the earliest polymers— is made by vulcanizing pure rubber with sulfur, usually between 25% and 50%. Its name derives from ebony, which the material began to replace in certain applications because of its durability and natural luster. The engraving Eboya Made in Tokyo confirms the origin and identity of this carefully crafted writing instrument.

Concept and design

The Small version is light, balanced and comfortable for writing with the cap posted or unposted. Its body is made from yellow marbled ebonite laid over a black ebonite base, using an original combination developed by Nikko Ebonite Manufacturing. Eboya translates Kogetsu as “Moon Shadow”. Golden yellow tones move across the darker material like moonlight meeting shadow, giving the pen a warm but restrained presence. Its smooth, secure surface remains comfortable during longer writing sessions. As the marbling is prepared by hand, every barrel displays a different arrangement of color.

Available colors

• Tanshin (True Heart): red
• Nichibo (Sunset): orange
• Kogetsu (Moon Shadow): yellow
• Wakaba (Fresh Leaves): yellow-green
• Kunpuu (Leafy Wind): green
• Shinkai (Deep Sea): blue
• Shinryo (Dragon God): beige
• Black ebonite: solid black

Please check availability and the estimated delivery time before ordering. Inktraveler works with real stock whenever possible and can also accept special orders when this model is unavailable.

Writing performance and filling system

The carefully adjusted 14K gold Bock #5 nib provides a smooth, precise and balanced writing experience. It is available in Fine, Medium Fine and Medium nib sizes. The pen uses an international cartridge or converter filling system compatible with brands such as Pelikan and Rotring (not compatible with Montblanc, Waterman or Caran d’Ache). Each body is turned, polished and assembled in Tokyo by the craftspeople of Nikko Ebonite Manufacturing. The accurate construction and individually patterned material give every finished pen its own visual identity.

Package contents

• Eboya Natsume Kogetsu Yellow Small Fountain Pen
• Standard international converter
• Ink cartridge (1 unit)
• Paulownia wood box (for Inktraveler, the standard cardboard packaging is replaced with this exclusive wooden case)
• Warranty

(Photographs are for reference and may differ slightly from the final product. The ebonite pattern is unique to every pen.)

Technical specifications

• Body material: marbled ebonite
• Color: Kogetsu Moon Shadow yellow over a black base
• Closed length: 132 mm
• Barrel diameter: 12.4 mm
• Cap diameter: 13.5 mm
• Clip: gold-plated
• Nib: 14K gold Bock #5
• Available nib sizes: Fine, Medium Fine and Medium
• Filling system: international cartridge or converter
• Made in Tokyo, Japan

Care and maintenance

Avoid prolonged exposure to direct sunlight or humidity and store the pen in a dark, dry place. Occasional cleaning with a soft cloth is enough to preserve its finish. Gradual changes in color or gloss are natural characteristics of ebonite and should not be considered material defects.

Brand history and philosophy

Eboya is the fountain pen brand of Nikko Ebonite Manufacturing, founded in 1952 and recognized as Japan’s last specialist ebonite manufacturer. After decades of supplying this material to the Japanese writing industry, the company introduced its own fountain pen line in 2009. Its Color Marble Ebonite was developed after old colored samples were rediscovered in the factory, prompting years of research into pigment behavior during vulcanization. That knowledge is visible in Kogetsu, where each combination of yellow light and dark ebonite forms a unique pattern.

"A quiet golden moon captured in ebonite, bringing light to every written line."