Futanari Eiyuu Heraclena no Bouken - Tanjou Hen | Futanari Heroine, The Adventures of Heraclena - Birth volume
that's in rock (Bessatsu Comic Unreal Sekka END ~Zetsubou no Naka de Sekizou e to Kaerareru Shoujo-tachi~ Vol. 1)
(C90) Rem no Ecchi na Nayami o Kaiketsu shitekudasai | Please Help Release Rem's Pent Up Sexual Frustration (Re:Zero kara Hajimeru Isekai Seikatsu)