On her train journey to Tokyo to be with her boyfriend, Nana Komatsu sits next to Nana Osaki, who dreams to become the next number 1 rock'n'roll superstar in Japan.

Sharing the same name, the two girls identify with each other, and as a matter of coincidence or by fate, happen to meet again while both were searching for an apartment in Tokyo to start their new lives.

The two women's lives may be destined to cross... they decide to share an apartment.
 

Innocence and sincere Nana (aka Hachi) and cool and confident Nana --- the two girls have totally opposite personalities.  Though they go through a number of clashes, they form a strong bond of friendship.