I asked the Project SEKAI community for all of their headcanons and received an overwhelming response of 125+ headcanons! Thank you so much to all of these people for contributing:

‪@MayonesaMitch‬
‪@smproject16‬
‪@1RuikasaFan‬
‪@Maeloaf‬
‪@Aerlixxie‬
‪@iShu56‬
‪@remi_______637‬
‪@__Gaykisser‬
‪@IrlKamishiroRui‬
‪@Darlingd0ll‬
‪@Vivia_Twilight‬
‪@bmalazarte9358‬
‪@moonzikoko‬
‪@aestaros‬
‪@Eis_.‬
‪@Unbelievablyunfunny‬
‪@Irl_NeneKusanagi‬
‪@sailorpanda‬
‪@colleenfischer2911‬
‪@AsukaRozenkreutz‬
‪@sailorbaguette‬
‪@shoujoreienjoyer‬
‪@rui.superfan‬
‪@chills_tiny_mom‬


This is a fan made video for HATSUNE MIKU : COLORFUL STAGE /
PROJECT SEKAI, the characters ft. include Miku, Mikudayo, Rin, Len, Ichika, Saki, Honami, Shiho, Minori, Haruka, Airi, Shizuku, Kohane, An, Akito, Toya, Tsukasa, Rui, Emu, Nene, RoboNene, Kanade, Mafuyu, Ena, and Mizuki. I hope you enjoy!

Here's the original audios used:
   • Undertale OST: 025  Dating Start!  
   • OMORI OST  045 Bargain Bin Boys  
   • Undertale OST: 055  Can You Really C...  
   • OMORI OST  015 Tussle Among Trees  
   • Undertale OST: 068  Death by Glamour  
   • Deltarune Chapter 2 OST: 17  WELCOME...  
   • Undertale OST: 049  It's Showtime!