how to improve massaging skill? it seems i got stuck and cant do anything
I'd imagine massaging would be more about a combination of inteligence and strength rather than a single skill in of itself. Considering giving a massage is more a combination of just knowing where specific points in the muscles are and being able to apply just the right amount of pressure to loosen said points than any actual technique this would make the most sense. While there are classes for that sort of thing you won't learn anything there that you wouldn't learn in a basic below college entry level anatomy class.
Go to the Shop where you can find Kaori and Yuri ... there you can buy 3 Massage Books (not all to the same time .. one after another) than go to your room and go on "Learn Skill" (3 Times) and you improved .. go to auroras and do your job untill you cant go on ... again to the Store ... and so on :-)