World's End Harem manga volume 11 features story by LINK and art by Kotaro Shono.

A vaccine for the MK Virus draws near, and with it, hope for humanity’s future! But it can’t come to fruition without some help from Reito’s blood! All the women who have helped Reito on his journey want to be the one to stimulate his male hormones to improve the vaccine’s potency. When he draws closer to Elisa, a shocking secret comes to light about her past. Who will Reito choose to be humanity’s last hope?