Most likely not. Usually, such works are the product of the author's imagination and creativity rather than being based on actual happenings. 'Pulang' seems to fall into this category.
One idea could be 'Sunrise Academy'. It gives a sense of new beginnings and hope, which could be great for a novel set in a school environment. The students could be seen as the 'rising sun' of the future.
It seems that Pulang Araw isn't based on a true story. It's likely a concoction of the author's imagination and story-telling skills to engage the audience.
A good name could be 'Mystic Grove School'. 'Mystic' gives an air of mystery and 'Grove' makes it seem like it's in a peaceful, nature - surrounded area. This would be perfect for a novel where there are secrets to be uncovered in the school grounds.
Archive of Our Own (AO3) is a great place to start. It has a large collection of fanfictions from various fandoms, including 'h2o just add water'. Just use the search...
The 'first omen story' could be a wide variety of things. It could be a story where the first omen is a strange dream that a character has, which then...
Hosea is into crime novels. He probably likes the mystery and suspense that these novels often bring. Crime novels usually have complex plots and interesting characters which can be really...
The Irish origin story includes the idea of a rich mythological past. There were the Tuatha Dé Danann, a group of supernatural beings. They were said to have ruled Ireland...
Perhaps there is a Reepworld family story of an old family feud that has been passed down through generations. But then, two young members from the feuding sides fall in...