Platinum 3776 Century Fountain Pen - Oshino

The Platinum #3776 Century Oshino Fountain Pen takes the familiar architecture of Platinum's flagship #3776 Century and gives transparency the central role. Introduced in 2018, Oshino was named for Oshino Hakkai, the group of clear spring-fed ponds near Mount Fuji. Platinum developed the pen around the same visual idea, pursuing a body with the clarity of water so that the internal structure and ink become part of the design rather than remaining hidden inside an opaque barrel.

Inspired by Oshino Hakkai

Oshino Hakkai is known for spring water fed by groundwater associated with Mount Fuji, making the reference especially fitting for the #3776 family, whose name reflects the mountain's 3,776-meter elevation. The high-transparency AS resin cap and barrel give colored ink an unusually visible role, allowing a change of ink to alter the appearance of the pen itself. Platinum extends the Mount Fuji theme with a specially shaped detail at the crown, while etched lettering on the cap ring creates a more dimensional finish without interrupting the clean demonstrator aesthetic.

Large 14k Gold Nib

The Oshino uses Platinum's large 14k gold #3776 Century nib with a rhodium finish. The bright rhodium surface complements the clear resin and silver-tone hardware, keeping the visual language consistent from the clip and cap bands through to the writing point. Our current Oshino selection spans Ultra Extra Fine, Extra Fine, Fine, Soft Fine, Medium, Broad, and Coarse nib options, making this listing useful for writers seeking anything from exceptionally narrow Japanese line widths to a much broader, more expressive stroke.

Slip & Seal Cap

One of the defining technical features of this generation of the #3776 Century is Platinum's Slip & Seal mechanism. The inner cap is engineered to maintain an airtight seal around the nib, reducing evaporation and helping prevent ink from drying during long periods between uses. Platinum originally stated that this version could remain capped for approximately two years and still provide a smooth start, a meaningful advantage for collectors who keep several fountain pens inked at once.

Cartridge and Converter Filling

Oshino uses Platinum's proprietary cartridge/converter system. Cartridges offer straightforward refilling, while a converter opens the pen to bottled inks and makes particularly good use of the transparent body. On a demonstrator like Oshino, the ink supply is not merely functional: it becomes part of the pen's visual character.

Collector Perspective

Platinum introduced Oshino as a regular-production #3776 Century model rather than a numbered limited edition. The first 3,000 production lots were accompanied by serialized blotter cards, a launch detail that is easy to confuse with a numbered pen edition. Its appeal rests instead on the purity of the execution: high-transparency resin, rhodium-finished hardware, a large gold nib, and Platinum's Slip & Seal system presented with very little visual distraction.

Technical Specifications

• Brand: Platinum
• Collection: #3776 Century
• Model: Oshino
• Product Number: PNB-20000A #5
• Writing Type: Fountain Pen
• Body and Cap Material: High-transparency AS resin
• Trim: Rhodium-finished metal
• Nib: Large 14k gold with rhodium finish
• Current Nib Options: Ultra Extra Fine, Extra Fine, Fine, Soft Fine, Medium, Broad, Coarse
• Filling System: Platinum cartridge / converter
• Cap: Screw cap with Slip & Seal mechanism
• Length: 139.5 mm
• Maximum Diameter: 15.4 mm
• Approximate Weight: 21.1 g