Seiu Ito (隡?????湧?? It? Seiu), also romanised as Seiyu Itoh (3 March 1882 in Tokyo - 28 January 1961 in Tokyo) was a Japanese painter, recognised today as 'the father of modern kinbaku'.

Ito was born Hajime Ito (隡????銝?? It? Hajime) in Tokyo's Asakusa district and started his education in painting by 1890. His father was a metalworker and he also received training in ivory carving, later sculpture. He adopted the alias Seiu (Sino-Japanese reading of kanji for words 'clear' and 'rain') at age 13. Around 1907, he began working for newspapers.

Ito became the target of censors in 1930, which led to the decline of his fortunes, and he lost most of his works during the Great Tokyo Air Raid. In 1960, he was recognised by the Japan Artists Association (?交??蝢?摰園???? Nihon Bijutsuka Renmei).

Kinbaku (蝺???) means 'tight binding' Kinbaku-bi (蝺???蝢? which literally means 'the beauty of tight binding'. Kinbaku is a Japanese style of bondage or BDSM. Shibari (蝮???) is a Japanese word that literally means 'to tie' or 'to bind'.

Bondage as a sexual activity first came to notice in Japan in the late Edo period. Generally recognized as 'father of Kinbaku' is Seiu Ito, who started studying and researching Hoj?jutsu is credited with the inception of Kinbaku, though it is noted that he drew inspiration from other art forms of the time including Kabuki theatre and Ukiyo-e woodblock prints.