[11] On 15 April 2022, Ouano made his AFC Champions League debut in a 0–1 defeat against Jeonnam Dragons, coming in as a substitute replacing Ricardo Sendra at the 83rd minute of the match.
[12] In 2016, Ouano was included in the 23-man squad for the 2016 AFF U-16 Youth Championship held in Phnom Penh, Cambodia.
[16][17][18] In 2021, Ouano was included in the 23-man squad for the 2022 AFC U-23 Asian Cup qualification matches against South Korea, Singapore and Timor Leste.
[19] He made his debut for the Philippines U23 in a 1–0 defeat against Singapore U23, coming in as a substitute replacing Mark Winhoffer at the 59th minute.
[20] Ouano scored his first and second goal for the Philippines U23 in a 2–2 draw against Timor Leste U23 in the 2022 AFF U-23 Youth Championship held in Cambodia.