The escalating geopolitical tension between China and Japan is spilling into their cultural sectors, raising fears of a broader boycott and placing K-pop in a precarious position. Korean entertainment companies hope their artists will remain insulated from the fallout, but they are watching developments closely. Signs of a possible cultural freeze emerged Friday when Maki Otsuki, the Japanese singer behind the theme song for the hit anime “One Piece,” was abruptly pulled off the stage during a c