They have been negociating with IS for months. The current threat is to disrupt the Japanses PMs visit to the region, and appears to have succeeded. A Japanese Special Forces operating could be mounted from Turkey, they are on good relations with Japan. But it might be cheaper to just pay up.
// // The Japanese man who was captured is believed to be Haruna Yukawa, a 42-year-old from Chiba, who started a military service company in January called PMC. He was apparently taken hostage by Islamic State militants on Aug. 14.
Meanwhile, a senior official of another Syrian opposition group, the Islamic Front, who was with the Japanese man shortly before his capture, said the Islamic State is willing to negotiate handing over the hostage with the Islamic Front.
The official told The Asahi Shimbun on Aug. 20 via telephone that when the Islamic Front proposed releasing the man in exchange for the release of Islamic State members it was holding as prisoners, the Islamic State said it was willing to talk.
"We would like to start full-scale negotiations soon," said the official, who declined to disclose further details. //