Komatsu Nana happens to sit next to Osaki Nana in the train for Tokyo. Komatsu Nana is going to meet her boyfriend, while Osaki Nana is going to Tokyo to become a musician. Because they happened to have same names, soon they become friends. Furthermore, when they’re looking for apartments, they meet again. Then, they began to live in the same room. After a couple weeks or so of living together Hachi aka Nana K helps Nana o find a new Bass Shinichi Okazaki. Hachi is in awe of Nana and slowly Nana becomes a major part of Hachi life. She unknowingly puts her boy friend on the back burner for her. While this is going on he befriends a co-worker by the name of Sachiko Kawamura. He falls for her and cheats on Hachi.
She realizes that she hasn't been spending a lot of tie with Shoji so she, Nana, and Shin go by his work for dinner and hope that she and him can do something later on after he gets off. He tries to not have Hachi and Sachiko meet . But however they do when Sachiko over hears them talking about Shoji and causes her to drop her tray of drinks, she tries to pick the broken glass up by herself and gets cut. Hachi comes over and tends to her Sachiko cries while she's tending to her saying I'm sorry over and over again.
Sachiko runs to the back and as Shoji is coming from out the bathroom sees her and runs after to asking her why is she crying. She tells him she can't see him anymore and that she won't her his girlfriend who is so nice and pretty so this is the end. After that happens Shoji finally comes up to Hachi and the rest telling her that they need to talk and she doesn't have to wait for him just go home.They leave but wait for him anyway at the back of the restaurant. shin gets a call and he leaves the girls. Nana asks Hachi why can't we just go home. she tells her she wants to show him how she is willing to be strong for him and surprise him.
After they finish work, Sachiko runs away from Shoji he follows her. She tells him its over she starts to cry but he won't listen. He grabs her by the arm and pulls her close saying that he'll tell her everything. Hachi and Nana watches this go on and then Shoji and Sachiko finally sees them Sachiko pulls away from Shoji and Nana Charges for Shoji. Sachiko jumps in the way saying that don't hurt him this is all my I knew he had a girlfriend and didn't stop so if you want to hit someone hit me.
Nana turns to Hachi yelling at her to fight for him or she'll lose him all she could do is cry as Nana pulls at her arm. She says softly I don't want to...see his face. then Nana takes her by the hand as they went home.
Hachi stays in bed for a couple days crying over Shoji. As the Blast live is coming up she starts to feel better at the live she meets a girl named Misato Uehara,a fan of Blast since the beginning they have a feast at home to celebrate the success of the live. The next day Hachi blows up at her because of all the attention Nana was giving her. After they got pass that they became friends.
After learning of Osaki's breakup with Honjo Ren, she wants to help the two to reconnect after realizing that they were still very much in love with each other. So,Hachi asked Nana to go to a Trapnest concert but she said no earlier but soon changes her mind. At the concert the two held hands and cried hoping that Ren would see Nana and get back together. After the concert Ren called Yasu he gave him Hachi number but he never called. Yasu called Nana and told her he gave Ren Hachi number she said she wants nothing to do with him. Yasu said if that's ture then give him the keys and hung up on, she called Ren asking to meet. when she got to his room she said I didn't come to get back together as soon as she said that Ren hugged her telling her how much he missed her. They kiss and make love.
When they get back home they have a reunion party of sorts, Nana invited Ren to meet everyone. To thank Hachi she had Ren bring along Takumi. A couple days went by and Hachi gets a phone call from Takumi asking her can they get together, he picks her up and they have sex. Hachi thinks to herself that this relationship would go no where but keeps it up. While Takumi is on tour she falls in love with Nobu.
She calls Takumi to break things off but he thinks she isn't serious. Things are going well for Hachi and Nobu, but she starts to fell sick at work and takes a pregnancy test. she keeps this from everyone and just tells them she had summer flash or something, she goes to the doctor and she confirms that she is pregnant. Nana tells Nobu that the reason Hachi hasn't be coming to rehearsal is due to the fact that she is sick he freaks out and wants to live practice but stays.
Hachi hears the doorbell she gets up she is startled that Takumi is at her door she answers it telling him to leave, but as she is talking to him she runs to the bathroom. He follows her and ask her is she ok after she finish throwing up she tells him she wants to keep her baby. That she wants nothing to do with him that the baby could be her boyfriend so not to worry. He leaves she finishs in the bathroom tries to go in her room but the door is locked Takumi is calling Nobu to tell him about her pregnancy. while Takumi is talking to Nobu, Hachi bangs on the door crying telling Takumi not to tell Nobu.
Nana is walking with Nobu when he gets the call Nobu passes the phone to Nana she demands Takumi gives the phone to Hachi. He does but Hachi is in a state of shock due to the fact that he told Nobu, he tells Nana that she's not in the mood to talk. Nan is hurt by the fact that Hachi didn't tell her she was pregnant. Takumi carries Hachi to her bed and tells her no matter what he is there for her and the baby.
Nobu gets to the house he is meet by Takumi. Takumi leaves and Nobu and Hachi have a talk Nobu leaves in tears. When Takumi comes back no one is there he gets frantic and looks for her. Hachi went to her friends house who talk her into doing what is right for her child and that's to be with Takumi. She put her child need and Nobu before her own. She comes home to find Takumi waiting for her she agrees to marry him and Nana comes home and they have a talk. Takumi goes in the room with Hachi he says he has to go to work but wants to fool around first she tells him no he'll be late he says he has time. She then brings up the baby he says its alright, finally she says it'll make Nana upset and he says the only person you should worry about upsetting is me and they proceed. Nana hears them and gets upset she bangs on the table and the strawberry glass falls then she throws the other on the floor and leaves.Nana and Hachi have a falling out due to this,Reira and Shin hook up she pays him for his services. When the details of Ren and Nana relationship is leaked blast
gets debut to ride the publicity. Nana and announced their engagement which causes Hachi and Takumi to delay their wedding. While Nana is away recording Ren and Reira spend some time together and are photographed holding each other. In order to come to some sort of terms with this Takumi and the Boss meet with the Search(a paparazzi magazine) and ask them not release this story. They want a even bigger story in exchange Takumi decided to do some manipulating by revealing his relationship with Komatsu to SEARCH, who decided to run that news instead. As such, the couple were formally married.
Then Search did some digging into Nana background and finds out that her mother abandoned her is alive and married with kids. They exposed this and Nana mother Misuzu Ozaki runs off. Early on Nana meet her little sister Misato Uehara early on. The Misato that the band knew was really Mai Tsuzuki, who borrowed Misato's name to feel like Nana's real little sister. Mai was the granddaughter of a man who was a lover of Nana's grandmother, and subsequently reading her grandfather's diary became a fan of Blast and Nana.
After that Shin is arrested for possession of marijuana which caused BLAST to withdraw from tour. Nana goes solo then they fast forward 6 years and they show Hachi and her daughter Satsuki and the rest at the apartment watching the fireworks. But Nana is not with them
It is hinted at that Nana disappears and is never seen again, throughout many manga chapters. She is seen, though, with long blonde hair, while there are many rumours and speculations that she is dead. A mysterious person sends Hachiko pictures of her singing, with the Ren lotus still on her arm. And Hachiko exclaims and breaks down crying, because she always believed that her friend wasn't dead, and that she waited for the day for her and Ren to be reunited again.