Nana Komatsu is a naive and unmotivated girl who spends her high school years chasing one crush after another. Despite repeatedly failing in her pursuit of love, her spirits never fade. At age 20, she boards a train to Tokyo, hoping to reunite with her current boyfriend.
Nana Osaki, in contrast, is feisty and proud. After joining a local band in high school, she falls in love with both music and a fellow band member. But when forced to choose between her relationship and her musical career, she picks the latter and parts ways with her boyfriend. On her 20th birthday, she takes the same train to Tokyo as her namesake, determined to become a top vocalist.
These two girls, sharing a name but having very different goals, end up seated together on their journey to the city, and as fate would have it, eventually share the same apartment. A deep and unique bond forms between them, and they support each other through a saga of love, music, friendship, and heartbreak.