[12] Ishiy's biggest individual title was gold at the 2019 Pan American Table Tennis Championships, held in Asunción, Paraguay.

Just over 70 minutes after the end of the semi-final, he faced Argentine Gastón Alto, another experienced athlete from the World Tour, defeating him by 4 sets to 1, with splits of (9–11, 11–3, 14–12 , 11–4 and 11–7) to win the gold medal.

[16] Ishiy was at the 2020 Olympic Games in Tokyo, where he participated in the Brazilian team made up of himself, Hugo Calderano and Gustavo Tsuboi.

[18] At the 2021 World Table Tennis Championships, Ishiy participated in the singles draw, being eliminated in the 2nd round by Quadri Aruna, who reached the quarter-finals of the competition.

[20][21][22] At the 2023 World Table Tennis Championships, Ishiy and Takahashi participated as No.11 seeds in the mixed doubles competition, where they were eliminated in the 2nd round by the Singaporean pair.

[23] At the 2023 Pan American Table Tennis Championships in Havana, the Brazilian team made up of Ishiy, Hugo Calderano, Eric Jouti and Guilherme Teodoro won gold.

With this, Ishiy, Hugo Calderano and Eric Jouti won the place to defend the Brazilian team at the Paris 2024 Olympic Games.

[26] At the 2023 Pan American Games in Santiago, Ishiy won gold for the Brazilian team, and silver in mixed doubles.

[29] In singles, Ishiy reached the second round, but was eliminated by Chilean Nicolás Burgos, second-ranked player in the Americas, number 54 in the world at the moment.