The State of Saigyo (Japanese: 西行国, Saigyō-koku), colloquially known as Saigyo (西行, Saigyō), is a sovereign state located in eastern Aphrodite Terra on planet Venus. Beginning as a series of Japanese settlements, the region gained independence in the 2000s. Unique among the Venusian nations, Saigyo is a constitutional monarchy under the Japanese realm.
Prior to the construction of Japanese settlements, the region was explored in depth by the Soviet Union as part of the unmanned Venera Program of the 1970s and '80s. Many milestones set on Venus would happen within Saigyo, including the first impact on another planet, the first soft landing, the first to transmit data from the surface, and the first confirmation of life outside Earth. The Soviet Union originally held claims to all of Aphrodite Terra (including Saigyo), but relinquished these claims following their ratification of the Venus Treaty.
The climate of Saigyo is predominantly humid and tropical, with much of the north being scattered with deserts. The Japanese people make up the majority of Saigyo's population, with sizable minorities of Brazilians, Chinese, Filipinos, and Koreans. Most of the population is centered along the coast of Dzerassa Planitia in the western portions of the nation.
The name Saigyo was coined in the early 2000s by the early Japanese explorers of the region, who named the area after Heian poet Saigyō. Many noted the poet's love for exploration and nature as being a symbol for Japan's efforts to colonize Venus.
High-speed rail lines have become a major means of transportation within Saigyo, being expanded upon following their independence. The rail systems are dominated by the Venus Railway Company (commonly referred to as JR Venus), which is a subdivision of the Japan Railways Group. The most common train models currently in use include the Shinkansen 700, the Shinkansen E5 S11, the Shinkansen Komachi, the 485-3000 series, and the Super Kamui train.