The vibes I got from this are basically "Oh, you were interested in my song? Here you go, there's the fucking song. Now how about next time you don't act like a little bitch about it?"
THAT'S how you do it Koga!
It's Eri and Mela. The one who gave Scarlet the Charcadet is obviously Mela (you can even see the bottom of her face in the next page), and you can also recognize Eri's Silhouette at the start of the flashback by heer hair and sleeves.