Eboya Houju Shinkai Deep Sea Medium Fountain Pen

Eboya Houju Shinkai Deep Sea Medium Fountain Pen

Eboya is the last factory dedicated to ebonite production in Japan. Each piece reflects a commitment to traditional craftsmanship and continuous innovation. The use of ebonite—one of the first polymers ever discovered—lends this pen a unique aesthetic: ebonite is produced by vulcanizing pure rubber with sulfur (between 25% and 50%), and its name derives from ebony, which it began to replace in certain applications due to its durability and natural shine. The engraving Eboya Made in Tokyo on the pen body is witness to its origin and excellence.

Concept and Design

The Houju model takes its name from the “宝珠” (Hōju), considered the property of dragons and said in tradition to bestow gold, silver, treasures, and anything one desires, as well as to help live life as one wishes, making dreams come true. This symbol, often depicted as a sphere or teardrop with a pointed tip, appears on the roofs of Inari Shinto shrines or in the mouth or under the paw of Inari’s messenger, the fox. It is associated with the ability to grant wishes, purify, and protect^[1][2][3]. Its delicate and rounded design, in the standard shape that facilitates cap closure, is complemented by a Japanese gold-plated clip that symbolizes the wish for this special piece to be preserved and appreciated for many years.

Functionality and Filling System

Fitted with a carefully tuned 14K gold nib, the Houju Shinkai Deep Sea Medium delivers smooth, precise, and balanced writing. It uses an international standard cartridge/converter filling system, compatible with brands such as Pelikan, Rotring, Faber-Castell, Kaweco, or Diplomat (not compatible with Montblanc, Waterman, or Caran d’Ache). Each body is individually hand-turned and polished in Tokyo, continuing the tradition of Nikko Ebonite Manufacturing’s artisan workshops. The perfect assembly of all its parts, along with the color of its ebonite, results in a piece of great beauty and quality.

Package Contents

• Eboya Houju Shinkai Deep Sea Medium fountain pen
• International standard converter
• Ink cartridge (1 piece)
• Premium paulownia wood box (Inktraveler uses this box instead of the standard cardboard packaging)
• Warranty

To preserve its finish, avoid direct sunlight and humidity, and store it in a dark place. Occasional cleaning with a soft cloth is enough to maintain its beauty. Images are for reference only and may differ slightly from the final product. Image credit for Houju on monument: By じぶろ - Own work, CC BY-SA 3.0, link.

Technical Specifications

• Body material: ebonite
• Color: Shinkai (deep sea blue)
• Closed length: 137 mm
• Posted length: 162 mm
• Body diameter: 13.5 mm
• Cap diameter: 15 mm
• Weight: approx. 24 g
• Nib: 14K gold
• Filling system: international cartridge/converter
• Made in Tokyo, Japan

Brand History & Philosophy

Eboya is the flagship brand of Nikko Ebonite Manufacturing, founded in 1952 and recognized as the last Japanese manufacturer specializing in ebonite. For decades it has supplied this material to major writing instrument houses such as Sailor and Pilot. In 2009, it launched its own line of fountain pens, combining technical expertise with Japanese aesthetic sensibility. Until 2016, production was led by master turner Noritoshi Kanesaki, disciple of the legendary nibmeister Kubo Kohei, contributing a unique artisanal legacy. Today, Eboya continues to create writing instruments that are durable, comfortable, and unmistakably finished.