Kidnapped (Kuroko no basket)

It was a normal day, Kuroko was walking home late at night, the same night Kuroko was kidnapped after days of waiting for there beloved Phantom to come to practice they ending up, finding out there beloved Phantom missing they search for days, weeks even months and it ending up to years but couldn't find there Beloved Phantom and they started to give up but for Kuroko, kuroko was beginning to think that they did not care for him, kuroko was waiting for them to come but they didn't come Kuroko ending up serving the kidnappers wish they didn't want to used him as a sex toy but instead they used him as a prodigy Assassin.....

What was the "kidnappers" after Kuroko, was it his low presence or something else..?