He only appears in a Pinya era inscription as "King" Myinsaing Sithu.
Sithu, who according to the inscription succeeded Uzana I, may have been a caretaker for his nephew and son-in-law Kyawswa I of Pinya.
Sithu's elder daughter Saw Gyi was married to Kyawswa I.
[1] At least one contemporary inscription donated by Kyawswa I's chief consort on 17 June 1342 disputes Sithu's claim, saying that Kyawswa I was already king.
[2] The king was likely Kyawswa I's maternal uncle since Kyawswa I's father Thihathu had only two brothers, Athinkhaya and Yazathingyan, both of whom had already died.