Heath Oslo's Organization

Heath Oslo is the primary antagonist of the Japanese visual novels and anime Grisaia no Meikyu and Grisaia no Rakuen. Oslo is an arms dealer and terrorist of Caucasian ancestry, but unknown nationality. It is not clear if Olso has political goals behind his actions, or is simply an arms dealer and mercenary contracted with others. Oslo is first introduced as a buyer of the art of child prodigy Kazuki Kazami, the older sister of Yuuji Kazami. Kazuki's death in a bus accident led to Yuuji's father becoming abusive to his wife and son, which eventually forced Yuuji to kill his own father to protect his mother, only for her to commit suicide soon after. After this event, Oslo took Yuuji in, treating him decently enough, if bizarrely- namely dressing him as his dead sister. When a client of Olso, attempted to force himself Yuuji, Yuuji was forced to kill again at the edge only ten. Heath witnessed this, and saw potential in Yuuji, and sent him to a "boarding school" in a foreign country, actually an illegal child soldier training camp part of a secret super-soldier program.

During his time at the training camp, Yuuji quickly proved himself to have a natural talent from marksmanship and close combat. Yuuji also befriended a girl named Marlin. Oslo noticed this and ordered Yuuji and Marlin to fight to the death as part of their "graduation". Yuuji failed to do this, and was brutally beaten, but survived. Oslo, however, gave him a second chance, ordering him to assassinate a member of the international criminal court in Canada. Oslo then went on to send Yuuji to assassinate people around the globe, while he used Marlin as a surrogate mother for Yuuji's clone. Marlin later died in childbirth.

Yuuji is rescued from Oslo's clutches by a Japanese special forces sniper named Asako Kusakabe during a raid of Olso's Japanese base of operations, one of the many mansions he is implied to own around the globe. Oslo is not seen again for several years. Yuuji, having presumably lied about his age, joins the Japanese Self-Defense Force after Asako's death, and is himself as lethal sniper. Oslo sends Yuuji's clone to attack an embassy in Tokyo, framing Yuuji for the attack and getting him arrested. Oslo then places portable nuclear warheads in Tokyo and threatens to detonate them unless they surrender the Thanatos super-computer, as well as Yuuji himself, to him.

Yuuji, however, is, against all odds, rescued from both Olso and the Japanese authorities by five girls Yuuji befriended when he spent a year "trying to live a normal life" while on leave, as well as a few of his old military buddies and his thought-to-be-deceased sister, Kazuki, who was, in fact, interfaced with Thanatos. However, they did not escape before Oslo placed a nuclear weapon in a locked braclet attached to Yuuji's wrist. This group manages to escape with Kazuki and Thanatos, while a JSDF unit disarms the nukes in Tokyo, but the one on Yuuji's person remains active, only able to be removed with a key on Oslo's person.

After his friends escape to an island in the South Pacific, Yuuji goes on alone to confront Olso, and boards the Thanatos, killing numerous guards, including the commander of Oslo's guards, Travis. Yuuji then confronts his clone on the flight deck of the carrier, and, after an extended gun and knife fight, finally kills him. Finally, Yuuji confronts Oslo and engages in combat with him. Heath Oslo, who severely wounds Yuuji with a katana, however, he is killed shortly afterwards when Yuuji stabs him in the back of the neck with a pen on his desk- a technique Oslo himself taught him. After Oslo's death, Yuuji detaches the nuclear weapon attached to his wrist with a key on Oslo's person, and escapes the Thanatos, which is later destroyed by the nuke-bracelet Yuuji left on board.