Seiko 5 Sports celebrates its 55th anniversary this year. To mark this historical milestone, the brand is releasing a limited edition Seiko 5 Sports watch (reference SRPJ91) in collaboration with Japanese superhero media franchise Masked Rider.
Created by manga artist Shotaro Ishinomori, Kamen Rider (also known as Masked Rider), is a Japanese superhero portrayed in several tokusatsu television programs, films, manga, and anime.
The franchise began in 1971 with the Kamen Rider television series. Takeshi Hongo, the primary protagonist of this highly successful TV series, wore a Seiko 5 Sports and used it as a communication device. The Japanese watchmaker took inspiration from this timepiece to design the collaboration model.

To create the Seiko 5 Sports 55th Anniversary Kamen Rider watch, the design of the original timepiece worn by Hongo has been upgraded with modern technology and materials, along with design cues that reference the Masked Rider 1.
Seiko 5 Sports SRPJ91 (SBSA207*) watch has a 42.5mm diameter stainless steel case. The dial color and pattern are inspired by the helmet of Masked Rider 1. Equipped with the automatic Caliber 4R36, this timepiece offers a power reserve of 41 hours.
On the exhibition case-back, you will find the Tachibana Racing logo, which is also used in the design of the motorcycle and belt in the film. The case-back also highlights “Limited Edition” and the serial number. Inspired by the scarf of Masked Rider 1, the back side of the calfskin strap features red color.
The Seiko 5 Sports 55th Anniversary Masked Rider comes in a specially designed box with overlapping acrylic plates that indicate the watch’s specifications.
Technical details
Model: Seiko 5 Sports 55th Anniversary Masked Rider (Kamen Rider) Limited Edition
Reference SRPJ91/ SRPJ91K1
*JDM reference number: SBSA207
Movement
Caliber 4R36
Automatic with manual winding
Power reserve: Approx. 41 hours
Jewels: 24
Stop second hand function
Day/Date display
Case
Stainless steel case
Thickness: 13.4mm
Diameter: 42.5mm
Lug-to-lug: 46.0mm
Crystal: Curved Hardlex
Distance between lugs: 22mm
Water resistance: 10 bar
LIMITED EDITION on the case back
Serial number engraved on the case back
See-through & Screw case back
Dial
Green
LumiBrite on hands, indexes and bezel
Day and Date display at 3 o’clock
Strap
Calfskin
Edition
Limited to 4,000 pieces worldwide (550 in Japan)
Approximate retail price
Japan: 51,700 yen (tax included)
USA: $450