Summer Bird Blue is about teenager Rumi Seto grieving for her younger sister Lea who passed away due to a car crash. The story repeatedly jumps from present to past and back. Every flashback to the happiest time when Rumi and Lea are the best siblings tugs on the my emotions. A lot of the book is reading about how Rumi feels from her lost sister. Surprisingly, she feels a lot of guilt and hatred towards herself for something that she had no control over. Eventually, she gets over the lost and writes a beautiful song that she and her sister were going to write together, Summer Bird Blue. The most moving part of the book was the ending where she finally wrote the song that she never brought herself to finish. Although the constant flashbacks seems to make the story less cohesive, it allows the reader to also become emotionally attached to Lea just like Rumi.