That is awesome. The mystery has been solved!
I love Bump of Chicken and Kamei.
A year ago, Fujiwara Motoo said that he married a "non celebrity woman", and "very important person". He is 10 years old than her. The tabloid says they took a picture of Fujiwara and a girl exiting a taxi together. The girl was wearing a wedding ring on her finger and they revealed it was Kamei. She met Fujiwara after her graduation and became friends. Fujiwara's hospitalization 7 years ago was a turning in their relationship.
Though, I'm not happy a tabloid had to reveal this for them.