2016 July updated.
Here is the list of Japanese persons who were killed by Islamic terrorists.
2003 November 29. near Tikrit, Iraq
Two diplomats, counselor Mr. Katsuhiko Oku (45 years old) and third secretary Mr. Masamori Inoue (30) were killed by unknown gunmen attack when moving by car. The unknown men's car approached Oku's car, then shot the diplomats and the Iraqi driver. All three died.
2004 May 27, in Mahmudiyah, Iraq
Two journalists Mr. Shinsuke Hashida (61) and his nephew Kotaro Ogawa (33) were attacked by unknown gunmen near Baghdad when moving by car. The car was shot and burned. Burned Hashida's body and Iraqi interpreter's body were found in the car. Next day, the body of Ogawa was found 10 km away from the scene. Ogawa was shot in his face.
2004 October, near Baghdad, Iraq
A tourist Mr. Shosei Koda (24) was captured by "al-Qaeda in Iraq" as a hostage. Al-Qaeda demanded Japanese government to withdraw Japanese forces from Iraq. Japan did not accept it. A few days later, Koda was beheaded. His body was found near Baghdad.
2008 August 26, in Nangarhār, Afghanistan
An NGO member Mr. Kazuya Ito (31) who supported Afghan local farms was kidnapped by a group of Taliban. Shortly he was shot and died.
2013 January, near In Amenas, Algeria
Many employees, including 10 Japanese working in a plant in Algeria died at "In Amenas hostage crisis". It was an attack by al-Qaeda-linked terrorists.
2015 January - February, somewhere in Syria or Iraq
A self-styled security contractor Mr. Haruna Yukawa (42) and a journalist Mr. Kenji Jogo a.k.a. Kenji Goto (47) were captured by "Islamic State" as hostages, and later they were beheaded. Islamic State demanded $200 million ransom or releasing the prisoner Mrs. Sajida Mubarak Atrous al-Rishawi in the Jordan prison. The demand was not accepted by both of Jordan and Japan.
2015 March 18, in Tunis, Tunisia
Chiemi Miyazaki (49), her daughter Haruka Miyazaki (22), and Machiyo Narusawa (66), these three tourists were killed by terrorists' gunfire when visiting National Bardo Museum. The Islamic State group claimed responsibility for the attack.
2016 July 1, in Dhaka, Bangladesh
Seven Japanese guests at a cafe were killed by a group called Jamaatul Mujahideen Bangladesh. Five terrorists attacked the cafe, and shot or stabbed the guests.