In an extraordinarily successful year, Oyu became champion of both the West and East divisions in JAF F4, and took two race wins at Sportsland SUGO and Suzuka to finish third in the latter championship behind Miyata and Sakaguchi.

Oyu went on to stun on his European debut, taking pole position and victory in both races and shattering the track's lap record by over seven tenths.

[5] However, despite garnering praise from Motopark boss Timo Rumpfkeil and being assessed for a spot in the Red Bull Junior Team, Oyu ultimately returned to Japan and has not raced internationally since.

[6] In December 2019, amid uncertainties over his future, Oyu received a last-minute call-up from TCS Nakajima Racing to drive in the Super Formula Championship's post-season test at Suzuka.

[7][8] Oyu impressed on debut at Twin Ring Motegi, going fastest in free practice and qualifying in fourth position - the highest of any Honda-powered driver, but suffered a puncture on the first lap and was relegated to the back of the field.

[14] Despite his strong results in the latter half of 2022, Oyu was dropped by Nakajima at the end of the year and was absent from the Super Formula entry list released by Honda in 2022, with his seat taken by former Red Bull junior Ren Satō, who moved over from Team Goh.

[18] In December 2023, Oyu partook in the Super Formula post-season test at Suzuka for the Toyota-powered P.mu/Cerumo INGING team, prompting surprise from within the paddock.

[20] Oyu made his debut in Super GT in 2020, racing for ARTA in a Honda NSX GT300 alongside veteran and two-time series champion Shinichi Takagi.

He has made numerous appearances on the Hot-Version video series (formerly Best Motoring) alongside racing driver and longtime host Keiichi Tsuchiya, often featuring his own car.