Because no poem survives which was definitely composed in the late period when the capital was placed at Fujiwara-kyo (the Imperial capital of Japan for 16 years between 694 and 710) or after the transfer of the capital to Heijokyo (the ancient capital of Japan in present-day Nara), he is considered to have passed away before the relocation of the capital to Heijokyo.
藤原京時代の後半や、平城京遷都後の確実な作品が残らないことから、平城京遷都前には亡くなったものと思われる。