Outer Halo 

When his band breaks up and Sora is feeling lost, he happens to attend a concert where he reunites with Naoharu Tamaki, an upperclassman from his middle school. "I know that voice..." A vivid memory from 10 years ago comes back to him. But there's a huge distance between Naoharu, shining in the light of the stage, and Sora, standing in the audience... The faint memory of his first love is reflected in these glittering lights. Sora and Nao's love story begins with a fated reunion. (Source: Kodansha, translated) Note: Includes one extra chapter.