My Yamaha Clavinova

My dream this year is to be able to play some of the 80's Jpops on my digital piano I bought over a year go...but I am having a tough time finding "sheet music"/piano book for those songs such as Halfmoon Serenade, Second Love, Saiai, Harunanoni, Kenkawoyamete, etc... if you know where I can find them, let me know..I will thank you big time