Rikei ga Koi ni Ochita no de Shoumei shitemita.

When researcher Ayame Himuro tells her colleague Shinya Yukimura that she loves him, the relentlessly logical scientist gives the most predictable response possible: how can they prove that this feeling is actually love? Instead of beginning an ordinary relationship, the pair turns the confession into a full research project. They measure heart rates, calculate physical distance, and recreate romantic situations while searching for conditions that could produce a scientific definition of love. Their laboratory friends are repeatedly drawn into the experiments, sometimes out of curiosity and sometimes because Himuro and Yukimura need comparison data. Yet the more graphs, equations, and controlled tests they produce, the harder one problem becomes to ignore: their determination to prove love may itself be the clearest evidence that it is already there.