Nana Komatsu and Masaki Suga had worked together in the movie Drowning Knife, but there was no mention of them acting in a TV series together. There was currently no relevant information regarding their cooperation in the TV series.
Since I don't know the real nana komatsu and masaki suda, let's imagine their love story. They could have been friends first. Then one day, nana komatsu got into some trouble and masaki suda was there to help her out. That event made nana komatsu see masaki suda in a new light. They started to spend more time together, and feelings of love began to blossom. Their relationship might have faced some challenges, like family disapproval or long - distance issues, but they overcame them through their strong love for each other.
As I don't have the real story, I can only speculate. Maybe their first kiss was a key moment. It could have been a very emotional and passionate moment that deepened their connection. Another key moment might be when they said 'I love you' to each other for the first time. It was a declaration of their feelings and made their relationship more serious.
To be honest, I don't have the exact count of how many Nana manga there are. It's best to refer to official manga sources or dedicated manga communities where you can get a clear and up-to-date number.