A key moment could be when Luffy gives Nami his straw hat to protect. In the One Piece world, Luffy's straw hat is extremely precious to him. By giving it to Nami, it shows how much he trusts and cares for her. Another moment is when Nami stitches Luffy's wound. Their closeness during this act can be seen as a sign of their growing affection. Also, when they face a powerful foe together and Luffy shouts out to protect Nami no matter what, it's a significant moment in their potential love story.
Zoro would be deeply affected. He has sworn to follow Luffy and his death would be a huge blow. He might feel like he failed in his duty to protect the captain. He would likely become more withdrawn at first, but then focus on getting stronger to avenge Luffy if there was someone to blame for his death.
One main sad moment was when Ash was separated from Pikachu. They are such a close pair, and being apart was really tough on them. It made Pikachu feel lonely and Ash felt like he was missing a part of himself.
Time is something that catches people off guard. The past has passed, the future has come, and only the present remains.
Those people who I thought would be together forever gradually disappeared from each other's lives. No farewell, no goodbye, only wishing you happiness.
When a special person appears in your life, you will, you will, you will start to live a different life. This is the meaning of love.
Leaving doesn't mean it's over, nor does it mean you can't start over.
Nami would be inconsolable at first. Luffy has always been there to protect her, and his sudden death would leave a huge void in her life. She would probably cry for days. As time passed, she would remember all the things Luffy taught her about courage and believing in oneself. Nami would start to take on some of Luffy's leadership qualities in a way. She would be more outspoken about her plans for the crew and more determined to see their dreams through. She would also keep Luffy's memory alive by telling stories of his adventures and his selfless acts to new people they meet on their journey.
Nami might be shocked at first. She'd probably look at Luffy with wide eyes, not believing what she just heard. After all, Luffy is not the most romantic or traditional suitor.
In some fanfictions, a very romantic instance is when Luffy first realizes his feelings for the reader. It might be a moment when the reader is sick and he's really worried. He stays by their side constantly, trying to make them feel better in his own clumsy but endearing way. Another great moment is when they are exploring a new island and Luffy holds the reader's hand to lead them through a difficult path. It's a simple gesture but full of meaning. And then there's the time when the reader makes a special piece of clothing for Luffy and he's so happy that he gives them a big hug and tells them how much he loves it, which is also a sign of his growing affection for the reader.
They might be shocked. Luffy's Gear 5 is such a powerful and strange form. In the fanfiction, characters could be amazed at his new abilities, like his cartoon - like movements and seemingly limitless power.