That day, when I met you, my world, where I couldn't even speak, was filled with music. High school student Fujieda Yuzuki is a kind girl who is liked by everyone. She prioritizes the people around her - her friends and her boyfriend - and hides her true feelings. She's not good at using her own voice. Putting others first had been Yuzuki's way of life up until then. That is, until she met you. One day, Yuzuki comes across a girl singing and playing the guitar on the street. Unable to forget the voice, she was humming a tune alone in the classroom after school when the girl from that time, Terada Hinata, appeared. It turned out to be a student at the same high school. What's more, she spoke to him, saying, "I've come from the future to save you" --!? A girl meets girl x school youth story!!