Etsuraku no Tane The Animation

When a tentacle monster takes up residence inside her body and starts using her as a weapon against other women, it marks the moment Itsuki Murasawa's ordinary life in a contemporary Japanese city is turned upside down. That's the setup, and it does not get lighter from there. The creature compels Itsuki to target people around her, including women she encounters in her daily life, and the real tension comes from watching her fight against something she literally cannot escape — because it's inside her. It's dark, it's uncomfortable in intentional ways, and it leans hard into the possession horror angle rather than just being gratuitous for its own sake. The animation from Studio Eromatick is detailed, the character designs are distinct, and there's an eerie atmosphere that keeps things feeling genuinely unsettling rather than campy. It's a single OVA episode, so it moves fast — no slow build, just straight into the psychological and physical conflict. If you've watched Tentacle and Witches or Dark Love and wanted something with a tighter narrative hook, this scratches that itch. The source is a WendyBell visual novel, so there's actual story structure underneath the surface. Don't go in expecting something lighthearted — this is firmly in dark horror-adjacent territory, and it commits to that tone throughout.