Why did Nai Nai meet Nana in Tokyo?

Nana Komatsu went to Tokyo to meet her boyfriend. On the train, Oosaki Nana, the lead singer of the rock band, sat with her. After arriving in Tokyo, they separated, but met in the same room and became roommates. Although their personalities are different, Oosaki Nana, who looks strong and decisive, and Komatsu, a simple and lovely Nai Nai, can complement each other in personality and become friends at home. ...

Nana is a cartoon for girls created by Japanese cartoonist ai yazawa, which tells a series of stories about two girls whose names are also pronounced Nana. It tells that in this world, you can always find someone with the same name as you. Maybe when you meet, your destinies will be intertwined.

References:

Baidu Encyclopedia _ Nana (Japanese ai yazawa creates cartoons)