In reality, Rin more or less starts it all, by pretending to be "Tsundere chan" et al. A) to practice her acting and B) get closer to this senpai who somehow stole her heart the moment they met.
Beyond that, my favorite part of the show and their relationship is that after Eiji, who is a year older, graduates and goes to college, Rin doesn't spend the entire last year of high school pining over him. She lives her life, hangs out with her friends, and continues her club activities, all very happily. She jumps at any chance to be with Eiji, but not to the absolute exclusion of everything else.
Is it overly saccharine sometimes? Sure. Do the characters ever address any flaws with one another? Nope. But I can definitely recommend watching this, especially as the story comes to a very satisfying, complete conclusion.
