BEAUTIFUL DAY DREAMER

The short centers on the Game Development Department of Millennium Science School, and shows Momoi being roped into various activities as she struggles to come up with ideas for a game's story. The ending theme song is called "Watashitachi no Quest" sung by members of the Millennium Science School's Game Development Department. (Source: Anime News Network, edited) — Description from AniList community (anilist.co).