Lyric

"Sayonara Crystal World" is a transparent youth song that depicts the delicate feelings and struggles of teenage girls, climbing the steps toward adulthood while being supported by their friends.
In the first verse, the lines "an eternal sweet summer day, if I follow the thin thread it leads to you, but I cannot stay by your side forever" express the protagonist's awareness that while time spent with close friends feels endless, graduation means these moments will never return. The chorus "even if I am swept away by busy days, I will open the door of hope and move forward" shows the determination to keep going beyond the transparent days of youth, aiming to reach the goals she has set for herself.
In the second verse, "only the sound of breathing echoes on the ground, I found courage in a notebook that said 'Fight!', and I felt I could live without looking down tomorrow" conveys gratitude for the sense of encouragement felt from friends even when working hard alone. In the following pre-chorus, "a common lie is seen through, I run outside still weak, even if everything turns into an illusion, I feel I can fly now" describes how the protagonist, burdened by insecurity and low self-esteem, tells a lie that is exposed by friends. Feeling ashamed, she runs out but realizes the depth of their bond, and discovers she can believe in her own potential when together with them.
After the instrumental break, the chorus "wandering as if always searching for something, shouting 'you fool' so loud the world shakes, what I want as I go in circles is a place to belong" depicts the outburst of emotions, the search for a solution to anxiety, impatience, and frustration.
The bridge beginning with "hey" shifts to a childlike tone born from the joy and reassurance of trusted friendship. In the final chorus, "at the sea we once promised to go to someday, we will meet again" conveys the positive feeling that even as they move toward different futures, they will always be able to reunite at that shared landscape of memory.
Musically, the arrangement fuses late 80s synth-pop with rock, adding modern depth and dimension. Driving rhythms and sparkling synths symbolize the brilliance of youth. The intro combines transparent synths with guitar riffs, pulling the listener into the story. Verses carry a subdued, melancholic melody, while the bridge slows down to create emotional contrast. The choruses burst with power and uplift, expressing friendship and determination toward the future in a dramatic way. The outro closes with the same synth sound as the intro, shorter in length, fading gently to leave a lasting sense of reflection.