Jun Samukawa is Yahiro's younger brother. He always wore a watch his brother Yahiro gave him on Lost Christmas. He had been affected with the Apocalypse Virus, which led to Yahiro becoming a drug dealer so that he could get treatment for the virus from the GHQ. Jun was able to see Yahiro's thoughts with the Apocalypse Virus and saw his brother as someone who hated him and thought that he was a burden. In Episode 9, Jun was killed by Yahiro's Void after begging Shu to kill him, as he does not want to die hating Yahiro or to burden his elder brother any longer.