The defending champion in the singles was Andy Murray , who started again this year, but he was eliminated in the semi-finals. In this year's final, the local Kei Nishikori defeated the Canadian Milos Raonic in three sets. Nishikori is the first Japanese in forty years to win the individual finals in Tokyo. For him it was only his second victory on the ATP Tour after the victory in Delray Beach in 2008.
Andy Murray also won the doubles title last year together with his brother Jamie . They also took part in the tournament together this year, but were eliminated in the quarter-finals. Alexander Peya and Bruno Soares won the title after beating the top seeded Leander Paes and Radek Štěpánek in the final . For Peya and Soares it was the third final participation in the current year and the second joint title.
The field of participants in the individual competition consisted of 32 players, that of the doubles competition consisted of 16 pairs. The total prize pool was $ 1,280,565 and total financial liabilities were $ 1,407,065.
The qualification took place from September 30th to September 1st, 2012. Four qualifying places were played, which entitle them to participate in the main draw of the tournament. There was also a lucky loser.
At the Rakuten Japan Open Tennis Championships 2012, the following prize money and world ranking points were paid out or credited for reaching the respective round. Players entering the main draw from qualification received the specified qualification points in addition to those for reaching the respective round. Otherwise the amounts are not to be understood as cumulative. The amounts for the double competition apply per player.