2.5th Anniversary Song Campaign was a song campaign celebrating Project SEKAI's 2.5th Anniversary.
Song list
| Release date | Song | Producer(s) | MV |
|---|---|---|---|
| 3/30 | Trash and Trash! | WADATAKEAKI (KurageP) | Original MV |
| 3/31 | Vampire's ∞ pathoS | Hitoshizuku×Yama△ | Original MV |
| 4/1 | METEOR | DIVELA | No MV |
| 4/2 | Interviewer | kuwagataP | Original MV |
| 4/3 | Watashi no Koi wa Hellfire | SLAVE.V-V-R | 3D MV |
| 4/4 | Snowman | halyosy | No MV |