Medaka Kuroiwa is Impervious to My Charms Vol. 9 (Kodansha, 2023)

Mona Kawai has just learned a shocking truth: her best friend Tomo has also fallen for Mona's crush, Medaka Kuroiwa! As if competing against one tough opponent wasn't bad enough, now Mona's got to battle her bestie in the fight for love. But will their friendship survive the strain? And with Christmas, one of the most romantic days of the year, right around the corner, there's precious little time left for Mona to secure a special date with Medaka-if she can ever bring herself to ask him out.