To find the author of this fanfiction, you could try searching on popular fanfiction websites. Maybe check Pokemon - related fanfiction platforms. It might take some time to sift through the stories, but that's probably the best way to figure out who wrote it.
Well, perhaps May realizes she loves someone else and has to break Ash's heart by telling him she can't be with him. It could be she has to leave for a far - off region for some important reason and knows a long - distance relationship won't work.
There could be many unknown authors out there writing fanfictions. It's hard to say specifically who the author of this one would be without more research. It might be some Naruto - loving fan who wanted to explore a more tragic and angsty storyline with these characters.
Hana could be an original character created for this fanfiction. Maybe she is a new ninja in the village who Naruto falls for, but she has a hidden agenda that ends up breaking his heart.
Definitely their Pokémon friends. Pikachu, of course, would be there. May's Blaziken and Ash's Greninja would also be among the guests. Their human friends like Brock, Misty, and Dawn would surely come. And perhaps some of the Gym Leaders they've met during their travels would also attend, like Roxanne from Rustboro City.
She could be a kunoichi from a small, unknown village who comes to Konoha on a mission. Naruto, being the friendly and trusting person he is, befriends her. But she has a hidden agenda and uses Naruto's feelings for her own ends, breaking his heart in the process.
Maybe it's a jealous rival of Naruto who wants Hinata for himself. He manipulates situations in such a way that Hinata ends up hurting Naruto. For example, he could stage events to make Hinata think Naruto has betrayed her trust.
Ino could be seen as the antagonist in this fanfiction. Since she's the one breaking Naruto's heart, she's causing the main conflict. Her actions are directly opposed to Naruto's happiness, which is a typical trait of an antagonist.
Another possible antagonist could be the Ministry of Magic. If they suspect Harry of something and force Tonks to spy on him or cut ties with him, it would break Harry's heart. The Ministry's strict rules and paranoia could be the driving force behind Tonks' actions that lead to Harry's heartbreak.
It could be a rival trainer. Rival trainers are often very competitive in the Pokémon world. Maybe this rival is jealous of Ash and May's progress and decides to betray them to slow them down. They might spread false rumors about Ash and May, causing other trainers to be distrustful of them.
In this fanfiction, Akeno is likely a character who has some sort of relationship with Naruto, either a friend or a love interest, who then does something to break his heart.