That can't be Cocoa Hoto. The girl's hair color is too dark compared to Cocoa's, her school uniform is browned out, her eyes are green and not purple, and Cocoa's kanji is ココア, not ココ or ココ千. Did you even look at the Twitter artist's profile pic?

Who said she's Cocoa? Did you even read that artist commentary, or at very least, try putting in google translation and see what pops out?
While you are at it, Cocoa doesn't even have a Kanji name.