To Nagisa, Kayano – or Akari as she prefers being called now – is more than just a simple friend. Despite the fact that he only knew her for a year, she quickly became his best friend and is just as important to him as Karma-kun used to be.
He didn't know when these feelings started. Perhaps it was way back when they first met, when she was still acting as "Kayano Kaede" and gave him his pig tails. To her, the gesture is simply to make him stand out more and help her blend in with the background characters but to him, it is much more different.
Nagisa, whom had no control over his life at that point, being cast aside by all his friends and dumped into the E-as-in-End Class. In the midst of that, along came a girl who doesn't make fun of him, cheerfully accepts him as he is and offers to be his friend. It meant a lot to him because for the first time in his life, Nagisa actually has someone to be there for him, to support him when things goes wrong, to encourage him when he is down, to be there by his side and will never leave him.
It was parts of the reason why he kept tying his hair into pigtail after all. Now that he looks back, Nagisa could have said no to Kayano when she offers him his new hairstyle but he never did. He even wears it every day since then instead. He kept the pigtails because it is a symbol that someone is there to support him in his darkest hour. Even when "Akari" dropped her act, he still couldn't take off that hairstyle even though he was that was most used by her. He felt like, if he took it off, he would truly lose Kayano, and he didn't want that to happen, no matter what…
After all the drama, she didn't stop being his friend even though she doesn't have any reason to (though things did get awkward between them for a short time after that). She was there when they stopped Shiro and the God of Death, she was there when they finally killed Koro-sensei, she was there when they finally manage to kill Koro-sensei, she was there when they graduate from Kunugigaoki, and she was here now, besides him, as they proceed to walk to their high school together.
To him, as "Kayano", she was simply a very pleasant person to be around with but as "Akari", he felt drawn to her closer and closer with every passing day. Her will and tenacity inspired him; she kept going on no matter how impossible the task is when he would have given up long ago.
"Once I decide something, I move straight towards it … that's how I am."
Nagisa smile, remember the memory fondly. She was always like that, stubborn and hard headed; even if he himself tries to make her change her mind, it'll probably take months, maybe even years. So it was really big shock to him when Akari admits that she do love him back then. After he uses the 15-hit combo kiss on her when she revealed her tentacles, he thought their friendship was beyond repairing at that point. But to his surprise, it's still there, and continues to develop into something…..more.
"Nagisa, what were you thinking about just now? You have been spacing out for a while now."
"I just thought about something, that's all."
He hugged Akari from behind and sighed contently. No matter what path awaits them in the future, she is his little pudding, and he will protect and love her with everything he had.