The Hissatsu series (必殺シリーズ, Hissatsu series) is a long-running prime-time popular television Jidaigeki series about assassins in Japan. Hissatsu Shikakenin is based on Shōtarō Ikenami's novel Shiokinin Fujieda Baian, but its sequels are only inspired by it. The series still continues as an annual two-hour special drama.