Ryuuhei Sasagawa

笹川 竜平

In the novel and manga, Boy #10 Ryuuhei Sasagawa is a member of Kiriyama's street gang with long hair. [Spoiler] After being told told by Kiriyama to meet with the other gang members at a certain point on the island, he, along with the other gang members, is killed by Kiriyama. [/Spoiler] (Source: Wikipedia)