Characters who are apart of Kouhei's group go here. When Kouhei Arita left the plane. A group of students followed him through. It consist of an unknown number of girls and 4 boys. There were numerous girls seen in the background, however none of them had been named.
After Hikari's death, the group had a disagreement whether to change their location (chapter 28). It is possible the group was splitted as the Kouhei led his group to the Limestone Cavern and the other group stayed at the same location near Hikari's death body. It could be made out of Unknown Girls listed below.
|Kouhei Arita||Yuki Sakuma||Okunoki||Kyouko|
|Tomo Sugiyama||Ueno||Miyajima||Kouhei's Group Boy|
|Unknown Female||Unknown Female||Hirabayashi||Kouhei's Group Girl|
|Unknown Female||Unknown Female||Unknown Female||Unknown Female|
- There is a possibility there were more females in his group, however these were all the ones shown.
- In chapter 8, there are two blondes, yet only 1 appears later on, leaving the other unaccounted for (the last two unknown females are the two blondes).
- It is unknown, but assumed that all the girls in Kouhei's group had died, except Yuki Sakuma.
- It is possible that the group splits into two after Hikari's death. Kouhei led his group into the Limestone Cavern and a group with a unknown number of girls stayed outside.
- On chapter 27 pages 18, Yuki recalled a flashback memory about 4 girls lying dead next to each other. Three of them are easy identified, Okunoki, Arita's Group Girl and Kyouko. The last girl left above should be Hirabayashi. However, later on, Yuki described her dead body in detail with blood stains everywhere on her body including her back. But on that page 18, the dead body is seen with no blood stains on her back.