──Shō Hashi, fearing Gosamaru’s skill and knowledge made his son the leader of Nakijin castle and moved Gosamaru to Zakimi Castle.

Gosamaru reconstructed Zakimi Castle around the year 1422. He rebuilt the castle almost completely from scratch, and this was the perfect chance for him to use the research he had conducted during his time at Nakijin Castle. Here is where he made the prototype of his arched gate which is said to be the oldest structure in all of Okinawa, a phantasmagoric and undefinable shape somewhere between a star and a pentagram. While most of the structure was made in the tofu masonry style, the kikkō midare style can be seen here and there throughout the structure. It is interesting to compare this structure to that of Nakagusuku.

It is said that Gosamaru was one of the best rulers of Zakimi Castle and thanks to his fair ruling, the peasants were able to build prosperous and fruitful farms. However, the reconstruction of Zakimi Castle required more manpower than the villagers were able to provide. There is a document saying that many people from the surrounding areas of Yoron-jima and Kikai-jima islands were coerced into helping with the construction. Another rumor claims that many of these people idolized Gosamaru and came of their own volition.