Seiko is a unisex Japanese given name that means 'clear' or 'honest'. It's composed of two kanji characters: 正 (seiko) meaning 'correct', and 生 (sei) meaning 'life'. In the Western world, Seiko is perhaps more recognized as the brand name for precision watches. However, its usage as a personal name predates the watch company by centuries.
Seiko is quite rare as a given name, with only eleven recorded births over nearly a century apart.