Gridman Sigma’s arrival at the end of the Boys Invent Great Hero short (2015).
Gridknight’s arrival at the end of SSSS.Dynazenon episode 6 (2021).
Akira Amemiya (Trigger) directed both the short & anime.
Gridman Playlist ►https://www.youtube.com/playlist?list=PLYyw1U2L42Ve7jJg2h09xyHBSGj3ts_l2
Like me on Facebook! ► https://www.facebook.com/180223srw?ref=hl
Follow me on Twitter! ► https://twitter.com/180223
#SSSSGRIDMAN #DYNAZENON #SSSSダイナゼノン