Within the ranks of the 4th Guard at S&D Securities, there is a group of skilled professionals renowned for their refinement - and Taki Keiichi is one of them. However, his talents have not gone unnoticed, and the notorious yakuza have set their sights on him. One particularly daring and reckless youth, Yuuki, has decided that Taki is the perfect recruit for their organization and will not give up until he succeeds.
"I won't leave until you either join us or end me," Yuuki declares.
Although Taki finds Yuuki's tenacity amusing, he invites the young man to stay as his personal bodyguard. Over time, however, Taki's power-hungry desires begin to grow, and he becomes obsessed with controlling Yuuki's unwavering subservience.