This is a Harmony House Fine China oval platter, pattern 3502 Starflower, made in Japan. The platter features a delicate floral design with blue starburst motifs and subtle silver or platinum trim. The backstamp confirms the model as "3502 Starflower" and indicates it was produced by Harmony House in Japan.
The china surface appears in excellent condition, with no visible chips, cracks, or repairs. See photos for measurements, if taken. This collectible serving platter is a popular pattern among mid-20th-century Harmony House designs.