Numata Gessai, also known by his artist name Utamasa, was a Japanese painter and printmaker born in 1787 who worked during the Edo period. He first studied under Maki Bokusen, then under Hokusai during that master's stay in Nagoya. In the 1840s he became a pupil of Cho Gessho, before going on to study the nanga manner under Yamamoto Baiitsu. His signatures reflect this lineage — some of his works are inscribed "Utamasa hitsu, pupil of Utamaro," indicating a connection to that tradition as well.
He lived in Nagoya and is known to have engraved and printed a number of surimono himself — the privately issued, luxury small-format prints that were exchanged as gifts among poets and connoisseurs. His surimono frequently depict intimate domestic scenes, such as a young boy on a veranda, a woman washing her hair, or the first water drawn at the New Year, and are often embellished with metallic pigments and embossing.