He played 22 matches and scored once as his side finished 16th and last in the final standings, however they retained their league status due to their being no relegation from the K-League that year.

His first year in Japan was spent largely as a reserve behind veteran right-back Akira Kaji and he made just 5 appearances as Gamba bounced back at the first time of asking, ending the season as J2 League champions.

Kaji departed for America before the season and Oh saw himself in competition with the newly acquired Koki Yonekura for the right-back position and Hiroki Fujiharu for the left-back slot.

They went on to concede injury time goals to Sho Sasaki and Yoshifumi Kashiwa and lost 3-2 before drawing the return leg 1-1 which led to a 4-3 aggregate defeat and Sanfrecce being crowned J League Champions.

[7] He was called up to the senior South Korea team by Uli Stielike for a 2018 FIFA World Cup qualifier against Lebanon in March 2016, but had to withdraw through injury and was replaced by Kim Chang-soo.