Yakusoku (2019)
English title: Promise
Japanese title: 約束
Alternative titles: The Promise
Type: Music
Source: Original
Episodes: 2
Status: Finished Airing
Aired: Sep 14, 2019
Duration: 4 min per ep
Rating: PG-13 - Teens 13 or older
Studios: Studio Gohan
Themes: Music

The video can be considered a prequel to Saikai.

Similarly, there are two versions of the video that are sung by Hatsune Miku on Niconico, and Harumaki Gohan on YouTube, both focus on a different girl.