'Stand Up! Sister' gives us simply more and more of the new/classic YUKI we love. But the real gem on this single is the coupling track 'koibito yo'. 'Koibito yo' comes out of nowhere with soft -yet catchy- YUKI vocals and a reggae beat, along with some excitingly innovative drum work. YUKI was already pregnant when she recorded these two wonderful hits. Her new-found and beautiful emotions come through clearly.