娜娜生母還活著的事情，被媒體報道了出來。阿八十分擔心，娜娜卻毫不介意，將全部熱情投入到首次的全國巡迴演唱。但卻發生了令人震撼的事情…！？

Nana K. was happy to be Blast's biggest cheerleader, but now that the band is taking off, she's discovering that there are hordes of fans eager to take her place. At the same time, her involvement with Trapnest hottie Takumi is turning into a romantic entanglement she hadn't expected. When a chance for another kind of happiness presents itself, will Nana K. be strong enough to face the difficult choices that result?

奈奈再次下定決心，今後將與拓實一起生活下去。另一方面，BLAST開始了地方巡迴演出。在大阪電台前的表演場地，等待著他們的是…？

世上的另一个我，不只是为了简单的寻找一个相同或者相似的灵魂。少女们自言自语的青春里总会渴望着自己不曾拥有的东西，如果当初也能像对方一样坦率或者坚强，会不会踏上一条完全不同的路？所以在频频回顾的同时也在默默的祝福，祝福着另一个自己，可以拥有幸福的人生。

Nana Komatsu is a young woman who's endured an unending string of boyfriend problems. Moving to Tokyo, she's hoping to take control of her life and put all those messy misadventures behind her. She's looking for love and she's hoping to find it in the big city. Nana Osaki, on the other hand, is cool, confident and focused. She swaggers into town and proceeds to kick down the doors to Tokyo's underground punk scene. She's got a dream and won't give up until she becomes Japan's No. 1 rock'n'roll superstar. This is the story of two 20-year-old women who share the same name. Even though they come from completely different backgrounds, they somehow meet and become best friends. The world of Nana is a world exploding with sex, music, fashion, gossip and all-night parties.

分開一段時間後， 與奈奈見面的機會終於來了。 就在夏天曾一度取消的煙火大會重新舉辦的那天， BLAST的成員在707號室等待這一刻的到來。 但是，奈奈的心卻產生了動搖……？

《NANA世上另一个我》主要内容：一个是温柔可人的邻家女孩，一个是桀骜不驯的摇滚少女，一个怀着简单的幸福，一个带着执着的梦想，当两个同叫“NANA”的少女在东京相遇，仿佛是冥冥中的约定，以另一种方式讲一个新新年代的两生花。我们爱NANA，因为那很可能就是我们自己，我们用自己的生活抒写着NANA的同人志。