Platinum Fuji Shunkei Limited Series
Four of the five Platinum Fuji Shunkei series pens feature a 14k gold nib and trim with rhodium plating. The fifth, Kinshu, features a gold nib and gold plated trim.
The following text comes from (edited) marketing copy. Images are property of Platinum Pen Japan.
Shungyo (2017)
The Fuji Shunkei series is inspired by the seasonal scenery of Mount Fuji. Shungyo evokes the dawn of early spring, when the freeze has not yet passed. Sunlight diffuses through the silent air, turning the sky red. The deep red body and incised markings mimic the light and frost. 3776pcs.

Kumpoo (2018)
The refreshing breeze that blows through the fresh greenery of Mount Fuji reaches up into the blue sky. The Kumpoo fountain pen evokes the blue and green colors of this pleasant seasonal scenery. 2500pcs.

Rokka (2019)
In winter, cold air and the silence of snow fill the atmosphere of Mount Fuji. Rokka evokes the pure and gorgeous view of Mount Fuji covered by snow and ice. 2500pcs.

Shiun (2020)
Purple clouds, or “shiun” in Japanese, have been an auspicious sign since ancient times. These clouds of good fortune appear around Mount Fuji, a site of worship for people over the centuries. The Shiun evokes the purple color the clouds paint the landscape of Mount Fuji. 3776pcs.

Kinshu (2021)
Kinshu is a beautiful autumn in which the trees turn red and look like Nishiki, a woven fabric patterned with various colored threads such as gold and silver. The Kinshu fountain pen evokes the scene of the heyday of autumn burning with autumn leaves. To represent the autumn leaves, the pattern cuts small curves that reflect the light through the body of the pen, like the threads of the Nishiki. The scarlet fire color resembles the flame of autumn as well. 4000pcs.

Rarity and Availability
All of these pens retailed for $300-500 when they were released. At the time of writing (May 2022), the Kinshu is 40% off from most retailers. That edition was not as popular as the previous releases. The Shungyo appears on eBay for $250-300. The Rokka can cost anywhere from $500-900 on the resale market. The Kumpoo is ridiculous: sellers on eBay list this at $1200. The Shiun is now sold out, but can be found on eBay and in r/Pen_Swap for $400-450.