Sei Shōnagon
Other important works of this period include the "Kokin Wakashū" (905), a waka-poetry anthology, and "The Pillow Book" (990s), the latter written by Murasaki Shikibu's contemporary and rival, Sei Shōnagon, as an essay about the life, loves, and pastimes of nobles in the Emperor's court. The "iroha" poem, now one of two standard orderings for the Japanese syllabary, was also written during the early part of this period.