If you've never read yuri, this the perfect story to start. At first you think that is going to be about a popular precocious girl seducing a shy, innocent girl... but it is not, in fact we get no yuri until almost halfway through the story and the way it happens is so natural but also a bit sad and surprising.
As expected from a Morinaga Milk Sensei story, character development is done extremely well and the pacing is excellent. There are some clichéd misunderstandings at some point, but they don't drag the story down.
If you want to read a romance story where you will be heavily invested emotionally in the main characters, and don't mind that both of them are girls, then I highly recommend Girl Friends to you.
~WiruSempai