Shikamaru would likely be lazy about getting involved at first. But if it started to cause a big ruckus in the village or among their group of friends, he'd step in. He'd probably analyze the situation quickly and try to find a logical solution. He might tell Naruto to cool off and Kiba to stop provoking Naruto if that was the case.
Hinata would be very worried. She has a soft spot for Naruto, and seeing him in such an aggressive state would be concerning. She might not be very vocal in stopping the fight, but she would try to get help from the other ninja around. After the fight, she would be there for Naruto, trying to understand his reasons while also hoping that he doesn't get in trouble with the village elders.
Sasuke would likely be very conflicted. On one hand, he has his own relationship with Naruto and Sakura. He might initially be angry at Naruto for attacking Sakura. But if he discovers the reasons behind it, he may understand Naruto's actions to some extent.
Shino might be a bit surprised at first but then be very supportive. He'd probably offer his knowledge of bugs to help in any way he could, like using certain bugs to detect any potential problems during the pregnancy. Naruto would be over - the - moon excited. He'd constantly be checking in on them, bringing over food and just being his usual exuberant self. Sakura would be the practical one, offering medical advice and making sure Hinata is taking proper care of herself during the pregnancy.
Hinata might be shocked at first. She is a gentle soul, so seeing Naruto be so violent towards Sasuke would be unexpected. But then she would probably try to stop Naruto, as she doesn't like to see people fighting. She might also feel a bit guilty, thinking that her relationship with Naruto somehow caused this conflict between the two friends.
Naruto would probably be shocked at first. He might not have expected Hinata to leave him for Kiba. He could be angry at himself for not noticing Hinata's unhappiness sooner.
Sakura would probably be really concerned. She has known Naruto for a long time and would want to make sure he's okay. She might try to talk to him and get him to open up about his feelings.
One possible reason could be a simple rivalry that has boiled over. Maybe they were competing for the same mission, and Naruto's determination to prove himself got the better of him. He might have seen Kiba as a threat to his goal of becoming Hokage, thinking that if Kiba succeeds in a high - profile mission, it could overshadow his own achievements.
Naruto would be extremely hurt. He loves Hinata deeply and to find out she cheated with Kiba would be a huge blow to him. He might go into a state of shock and disbelief at first.
Sakura would probably be shocked at first, but then she'd be supportive. She might offer her medical skills to help with Tenten's pregnancy. Shikamaru would likely think it's a troublesome situation but would also offer his strategic advice on how to handle things. Kakashi would be his usual calm self and give them some wise words about responsibility and family.
Naruto's friends like Sakura and Kakashi might be initially shocked. Sakura, as a medical ninja, would offer her medical expertise to help Cana during the pregnancy. Kakashi would probably be more reserved but offer his wisdom and protection. On Cana's side, her friends from her own world might be skeptical of Naruto at first, but as they see how much he cares for Cana, they start to accept him.
Sakura would be really happy for them. She has seen Naruto grow and has always wanted him to find true love. Since she has moved on from her old feelings for Naruto, she would be supportive and might even offer to help with the wedding preparations. Shikamaru would probably be a bit lazy about it at first, but deep down he'd be glad for Naruto. He'd say something like 'What a drag, but if it makes you happy, Naruto.' Kiba would be excited, especially since Hinata is his teammate. He might tease Naruto a bit about finally getting the girl.