- Bats Left, Throws Left
- Height 6' 0", Weight 165 lb.
- School Hakuoh University
Oscar Nakaoshi pitched for the Brazilian national team in the 2008 Americas Baseball Cup at age 17; he was 0-1 with a 2.08 ERA, allowing 6 hits and 3 runs (one earned) in 4 1/3 IP while fanning four. He started and took the loss against Venezuela after pitching scoreless relief in his first two outings. The left-hander set his college's record in wins (28), following fellow Brazilians Rafael Fernándes and Hugo Kanabushi to Hakuoh University in Japan. He pitched for Honda in the industrial leagues after college.
He then was on Brazil's roster for the 2013 World Baseball Classic Qualifiers. He started against Colombia and shut them out for four innings on five hits, two walks and four strikeouts against a lineup with four future, past or present major leaguers before Carlos Yoshimura relieved; Brazil won with Yoshimura getting the decision. Brazil would win a spot in the 2013 World Baseball Classic. In the Classic, he relieved Murilo Gouvea with a surprising 3-2 lead over defending champion Japan in the top of the 7th. He struck out Nobuhiro Matsuda and Hayato Sakamoto then got Kazuo Matsui on a grounder. In the 8th, though, he ran into trouble. Seiichi Uchikawa singled, Yoshio Itoi bunted him over and Hirokazu Ibata singled to tie it. Kesley Kondo relieved and let the inherited runner score, tagging Nakaoshi with the loss. He then got the start and did very well versus China (4 IP, 4 H, 0 R, 0 BB, 6 K) before Gouvea relieved and took a 5-2 loss when fading in the 8th.