I Want To Drink Your Tears

Imekai Kippei, a high school student, confessed to Arisa Umegami, an admired senior at his school, that he was ready to be rejected, but unexpectedly he got the OK and she decided to go out with him. Ippei was overjoyed, but Umegami-senpai asked him to make a certain condition as a "relationship"...?