Separation

Separation (分離, Bunri) is the 5th chapter of Volume five and 39th chapter overall.

Plot
L is thrilled by this new discovery, which suggests that killing criminals may have not been Kira’s true goals after all. It’s likely that it was just a cover-up in order to increase profits for the Yotsuba company. L, however, points out that this may be a new Kira who is probably an adult seeking monetary gain, unlike the first and Second Kira.

Light's research pays off when he finds that three people who held important positions in the Japanese business world had died of heart attacks. After these deaths, Yotsuba’s stock soared. However, Light also notices that important people in the business world had suddenly died through other measures like accidents, suicide and cancer. L finally concludes that Kira can kill in ways other than a heart attack.

They all agree that the most likely theory is that Kira or someone with Kira’s powers is among the Yotsuba group. They are determined to infiltrate the company. Meanwhile, Deputy Director Kitamura talks to Soichiro about the future of the Kira Investigation. Kitamura tells him that politicians have been accepting bribes from Kira, and the police have given up the case. He gives Soichiro a choice: the team will either stay with the NPA and stop the Kira Investigation or quit the NPA to continue working with L.

Soichiro tells the rest of the team about the situation and has decided that he will continue the investigation and quit the NPA. L, however, feels that the whole team should return to the NPA and promises that he will be fine working on this case alone.

Conception
The chapter's title "Separation" refers to the end of the effort sharing between the National Police Agency and the Japanese task force. Ohba said that he believed that he had "too much fun" with naming the previous two chapters, so he went "back into serious mode" for this chapter.