Place it at the very beginning of an edit, before any title card or first scene, then follow it with a background music loop to carry the opening into your main content. After that music has set the scene, bring in a short reaction sound for the first reveal or highlight.
このサウンドについて
This is a short musical intro, lasting about fifteen seconds, made to open a playlist and set up the tracks that follow. It feels calm and expectant, like a quiet moment before the music begins, giving listeners a chance to settle in and focus. That sense of a proper beginning makes it work as an opening rather than as a standalone track.