It's not a big deal, but it's getting long, so I'm writing it as an article...
Regarding the title's subject, this was my own decision (at least, at the time...)
I occasionally see comments blaming the management for this, so I want to clear up the misunderstanding.
My work, "Chururira Chururira Daddadda!"
It is included in Project Sekai, but the original Vocaloid version is not.
When I received the offer for inclusion, I knew nothing about Project Sekai (in fact, it was probably before the service even launched).
At that time, hearing "a new Vocaloid rhythm game," what I imagined was naturally something like Project DIVA.
What I thought then was:
"With the style of DIVA's visuals, since the characters themselves would be following the song's world-building, I probably wouldn't be able to tolerate even the slightest difference in interpretive direction in the staging..."
Those who have read interviews related to "Bless Your Breath" can probably guess that the Wada Takeaki of that time would think such a thing...
With that mindset, I made it so that only the cover version without Vocaloid characters was OK.
If it's a cover, it doesn't matter how much it deviates from my intentions.
However, this was obviously a complete misunderstanding, and after learning later that there are patterns where the original MV is included as-is, I am normally and thoroughly regretting it.
(By the way, what I regret even more is that I had received an offer for another song before this one, and I turned that one down completely.)