In September 1990, when Ramos was 33 years old, he was called up for the Japan national team for the 1990 Asian Games. On 26 September, he debuted against Bangladesh. After his debut, he became a regular player for Japan. He was a member of the Japan team that won the 1992 Asian Cup and he played 4 matches in the competition. Under manager Hans Ooft, Japan progressed to the final qualifying stage of the AFC for the 1994 World Cup. Ruy Ramos was on the pitch when Japan's hope to play in the finals was dashed by an injury-time Iraqi equaliser in the last qualifier, the match that the Japanese fans now refer to as the Agony of Doha. In 1995, Ramos also played at King Fahd Cup. He played 32 games and scored 1 goal for Japan until 1995.