Hoshi ga Matataku Konna Yoru ni (The Stars are Twinkling on a Night Like This) by Supercell with English/Romaji/Kanji subtitles. This song was first released on the "Utakata Hanabi" single and later included on the "Today is a Beautiful Day" album.
Easily one of my favorite Supercell songs. Nagi sounds even more amazing than usual.
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