Graduate students Shinya Yukimura and Ayame Himuro collaborate in the same lab. Ayame unexpectedly confesses to Shinya that she thinks they are in love one morning, startling him to the core. Shinya inquires as to how Ayame arrived at such a conclusion and clarifies that, as scientists, they are unable to draw the appropriate conclusions without supporting data.
The two start by attempting to categorize and quantify their feelings for one another and assert that, in order for love to be real, it must be demonstrable through science.