Koishi Tagari no Blue

From Aerandria Scans:
“Won’t you become my girlfriend?”
On the day of her high school entrance ceremony, Ao got asked that by Riku, a guy that she has only just met. But by that, he meant to ask her to become his fake girlfriend, just to pretend. Ao was surprised by the sudden request, but after knowing Riku’s true feeling, she decided to agree to become his fake girlfriend...?