The introduction of the TSUYOSA collection marked a significant milestone in CITIZEN's range, as it heralded a phase in which CITIZEN began using stainless steel for its watches—a unique feature, as many other affordable watches at the time were still made of brass. The TSUYOSA series in steel was not only more robust but also more elegant, and stood out for its fine finish. This included a filigree surface finish on the top of the case, which formed an attractive contrast to the highly polished bezel and the middle links of the bracelet. The models became well known for their luxurious design and meticulous attention to detail, and were particularly popular in the late 1990s and early 2000s.