Only Brown Bear knew exactly what Kuro is. Since she is the only one not amazed by Kuro's release.
"Who Will Know", is from the OST of Shin Godzilla, and is considered to be the titular version of our favourite Kaijuu's "Image Song"/"Villain Song".
Kuro, try and recall the feeling you had at the time you were fighting the Cerulean Queen.At that time, you brought out your presence and force of will, right?