Holding Eleanor’s hand was like holding a butterfly. Or a heartbeat. Like holding something complete, and completely alive.
This quote, which occurs in Chapter 15 and is from Park’s perspective, represents the first time that Eleanor and Park make physical contact with each other. Eleanor is upset because Richie called her rude names after Park came over, and she doesn’t want Richie’s horribleness to taint her entire relationship with Park. When Park takes Eleanor’s hand, Eleanor and Park become acutely and immediately aware of how much they like each other. The handholding scene also echoes the scene in Romeo and Juliet in which Romeo and Juliet first meet and fall in love. “For saints have hands that pilgrims' hands do touch, / And palm to palm is holy palmers’ kiss,” Juliet tells Romeo, comparing touching hands with kissing.
Park has held hands with girls before, but because he has never before felt a romantic connection with them, he hasn’t feel anything beyond being just friends. But with Eleanor, holding hands sparks the much deeper attraction that has been building between them. This seemingly tiny action opens up a whole world of possibilities. To Eleanor, Park’s touch makes her forget all her worries, since all her senses are drawn to this single spot on her body. To Park, Eleanor’s hand feels more vivid, beautiful, and alive than anything else in the world, because he is falling in love with her.