19-year-old Kubo has impressed on loan at Real Mallorca this season and Madrid are ‘delighted’ with him.
They knew how talented the Japanese youngster was, but did not expect him to adapt so quickly to European football.
Madrid chiefs have thought carefully about what to do with Kubo next season and want him to join a team fighting for European football.
Real Sociedad in pole
With that in mind, Real Sociedad is the destination most favoured within the Bernabéu offices.
Relations between Madrid and Sociedad are good from past deals, and La Real have a reputation of trusting youngsters.
Kubo will make the final decision but has shown a willingness to do what Madrid think is best for him.
According to AS, Kubo is unlikely to go abroad because Madrid want him to continue his European adaptation in La Liga.
But of the options that have come from abroad, AC Milan is the one Madrid like the most.
The Japan international does not plan to go to Serie A, but if he changes his mind Madrid would look favourably at Milan.
Kubo has made 30 appearances for Mallorca this season – 19 of them starts – and has three goals and four assists.