Natsu no Hi to Kimi no Koe (夏の日と君の声)

"Natsu no Hi to Kimi no Koe (夏の日と君の声)" is a song performed by ChouCho. In 2014, it was used as the first opening theme for the TV anime Glasslip (グラスリップ), a series animated by P.A. Works.

The song was issued in 2014 as ChouCho's ninth single, and its lyrics were written by ChouCho. The CD single included four tracks: "Natsu no Hi to Kimi no Koe", "Understand", and instrumental versions of both songs; the title track was later included on the album secretgarden.