Watashitachi ni wa Kabe ga Aru.

"If you want a boyfriend that bad, I'll go out with you." Growing up next-door neighbors, Reita Kikuchi and Makoto Sakurai's parents are friends, and the two of them have known each other forever. But one day Makoto is suddenly thrown into a relationship with that narcissistic and self-absorbed playboy, Reita—her old childhood friend! Follow Makoto's adventures as she navigates the ups and downs of dating the egotistical boy-next-door in the first installment of this romantic comedy!
(Source: Kodansha USA)
Note: Includes eight extra chapters.