3.5th Anniversary Song Campaign was a song campaign celebrating Project SEKAI's 3.5th Anniversary.
Song list
| Release date | Song | Producer(s) | VIRTUAL SINGER ver. singers | MV |
|---|---|---|---|---|
| ? | Electric Angel | Yasuo | Hatsune Miku | No MV |
| ? | ○○○○○○○○○○ | ? | ? | Original MV |
| ? | ○○○○○ | ? | ? | No MV |
| ? | ○○○○○○○ | ? | ? | Original MV |
| ? | ○○○○○○○○ | ? | ? | No MV |