It has been 10 years since Momo "Maki" Makimura's first relationship ended, but she still has not gotten over her feelings for Midori Oonishi, who broke up with her because they were "getting too old" to date. However, after a chance encounter, the two meet again, and Midori invites Maki to her house. There, she finds out that not only is Midori getting married but she is also pregnant. Maki wants to congratulate her, but her intuition tells her that something is off. The more she hears Midori talk about her soon-to-be-husband, the more red flags she notices. Later that night, she encourages Midori to run away with her.

Kakeochi Girl follows Maki as she attempts to find a way to help Midori while exploring the unwavering feelings between them.