Kitadai was born in São Paulo, Brazil, and is a member of the athletic club Barueri in São Paulo and the club Sogipa.[2][6][7] He is coached on the Brazil national team by Luis Shinohara and Mario Tsutsui.[8]
On July 28, 2012, his 23rd birthday, Kitadai won a bronze medal in the under 60 kg category at the London 2012 Olympic Games.[14] He won by beating Davaadorjiin Tömörkhüleg and Eisa Majrashi before losing to Rishod Sobirov. Because Sobirov reached the semifinals, Kitadai was entered into the repechage. In the repechage, he beat Choi Gwang-Hyeon and then Elio Verde to win the bronze medal.[15] He carried the medal everywhere.[16] On July 30, he damaged the ribbon and dented the medal when he dropped it in the shower.[16][17][18] The IOC issued him a new medal at the request of the Brazilian Olympic Committee. The medal reportedly contains only $4.71 worth of metal.[16][19]
Participating in the 2013 Judo World Masters (second most important competition on the judo circuit after the World Championships), Kitadai won a bronze medal, repeating his performance from the 2012 Olympics.[20][21]
At the 2015 World Judo Championships, Kitadai had his best individual appearance at the World Championships, finishing in 5th place. He reached the quarter-finals where he was beaten by world number 2 Ganbatyn Boldbaatar of Mongolia. In the repechage, he beat Choi In-hyuk, from South Korea, to advance to the bronze medal match. And, in the match that was worth the podium, Kitadai lost to the Japanese Toru Shishime.[25]
At the 2017 Judo Grand Slam Abu Dhabi, Kitadai won a silver medal. He reached the final and only lost the gold because he was punished three times. It was his first podium after being away for a long time recovering from surgery on his right shoulder.[27]
Kitadai obtained one of his biggest individual titles in May 2019. Participating in the 2019 Judo Grand Slam Baku (Grand Slam is the tournament that gives the most points in the judo ranking after the Olympics, the World Championships and the World Masters), he obtained the gold medal, winning five fights.[28][29]
Retirement
Kitadai announced his retirement in March 2022.[30]
Post-career in judo
Between January 2022[31] and September 2023[32] he worked as a youth national trainer for Austria Judo.