There is so much groundwork laid in the first episode, yet it has this lovely languid thoughtfulness that pervades throughout. The writer has set most of the first episode in junior high, and accurately captures the daily life of a school.
It is the acting of our two main leads that draws us in. She is completely believable as the dewy new teacher, full of hope and good intentions. He is completely believable as a junior high boy full of sharp opinions and bursting feelings. The microexpressions convey all their fleeting thoughts, from Akira reacting to the surprisingly gentle humor of Hijiri, to Hijiri wilting under Akiras hard questions. His outburst at the end, when he declares his feelings for Hijiri is brilliant, capturing both the excitement and then confusion of "now what do I do?"
I feel the poem serves as a metaphor. Love, like the spring rain, is quietly inexorable, coming in and changing everything.