Some of his friends were probably shocked at first. But then they might have become curious.
His friends' reactions could be mixed. The more open - minded ones might have been excited to read it and complimented Naruto on his creativity. However, those who are more traditional or conservative in their thinking might have been a bit taken aback and not known how to respond.
At first, Naruto might be really confused. He's used to thinking of his friends as his support system, so when they turn on him, he doesn't understand why. He'll probably try to talk to them, to ask what he did wrong. If they don't listen, he could become really sad and withdrawn. Maybe he'll start training even harder, using the pain of being rejected by his friends as motivation to become stronger.
His friends might be shocked at first, but then start to really enjoy reading it and discussing the ideas in it.
Shikamaru might just sigh and say something like 'What a troublesome thing to do, Naruto.' But deep down, he would also be a bit curious about why Naruto decided to dye his hair red.
His friends were probably very worried. Sakura, being a medical - ninja - in - training, might immediately start looking for symptoms and trying to diagnose him. Shikamaru could be thinking of strategies to keep Naruto safe while he's sick. And Naruto's other friends would likely offer their support in different ways, like bringing him food or just staying by his side to keep him company.
He would be heartbroken. Naruto values friendship above almost everything. At first, he might not believe it and try to reason with his friends.
Naruto would be extremely hurt. He values his friends above almost everything, so their betrayal would be like a knife to the heart. At first, he'd probably be in disbelief and try to reason with them. When he realizes they won't listen, he might become angry and lash out. But deep down, he'd still hope to win them back.
Ash could respond in different ways. He might try to confront his friends immediately to get an explanation. If the betrayal is really bad, he could cut them off completely and focus on his own goals, like becoming a better Pokémon trainer. He would also probably have some internal struggles, as he has memories and experiences with these friends that he can't just forget.
He might be extremely hurt. Harry could go into a state of shock and disbelief at first. He may isolate himself, not wanting to trust anyone else for a while.
Naruto might initially be shocked or confused. For example, if they prank him with the fake ramen, he'd probably make a really funny face when he takes the first bite. But then he'd probably laugh it off because he has a good sense of humor.
He might initially be in shock and disbelief. Naruto has always valued his friends highly, so it would be a huge blow to him. He could try to reason with them at first, asking them why they are doing this.