片っ端からぜんぶ恋 ; Katappashi Kara Zenbu Koi!!
From Hoshi Kuzuu:
Out of the blue, childhood friend Takaoka confesses to Iwami! When popular playboy and ladies man Takaoka says “I love you”, he doesn’t believe it one bit. Is he making fun of the virgin!? A modern high-school boys’ adolescent love development!
– chapter 2