Golgo 13 is hired by a mafia boss to kill another heavy-handed mafia boss. The targeted boss learns of Golgo's attempt to have him assassinated and installs bulletproof glass and sends emissaries to analyze Golgo's handgun response time in order to figure out countermeasures against the mercenary assassin. Golgo 13 must now find a way to defeat the bulletproof glass and overcome research of his own abilities while avoiding three assassins sent to kill him.