Okubo had his first international success at the 2017 Junior World Championships in Špindlerův Mlýn . There he won the gold medal in Big Air and was also fifth in Slopestyle . At the beginning of the 2017/18 season he started the World Cup in Cardrona for the first time and finished 43rd in slopestyle. At the beginning of December 2017 in Mönchengladbach he achieved his first podium finish in the World Cup with second place in the Big Air at his fifth World Cup. This was followed by two more top ten placements and at the end of the season eighth place in the Freestyle World Cup and second place in the Big Air World Cup. At the 2018 Winter Olympics in Pyeongchang , he finished 18th in Big Air and 14th in Slopestyle.