La ciencia del amor 1x3

When Himuro finds out that her junior in the Ikeda lab, Kosuke, has spent over 220 thousand yen on his beloved Aika and holds her every night when he goes to sleep, she is shaken by the realization that the only present she's ever given Yukimura is a notebook, and that she's never held him while she slept. She worries that she can't objectively call what she feels "love." As Yukimura and Himuro endlessly debate "love" using numbers, Kanade proposes that the two of them go on a date, but...