The main character even has a reason for this relationship with his sisters. This young man's uncle, called Yui, brought back a strange bottle called the "Inanna Vial" from a business trip. On this bottle lay a curse that could only be broken with the help of "women's juices." Yui had no need to go looking for suitable candidates, for he shared the roof with three charming, (so be it - half-sisters). After all, whoever could fill the bottle with "lady juice" and lift the curse would be granted one wish. And "Vial Inanna" with pleasure "prompts" the young man a good time to hunt for the coveted liquid ...