Yakusoku (2019)
English name: Promise
Type: Music, Episodes: 2
Aired: Sep 14, 2019
Studio: Studio Gohan
Source: Original
Rating: PG-13 - Teens 13 or older
Synopsis:
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.