I was rewatching H2O season 1 when I realized something: when te think about, each original character has had their own season that sort of resolved around them. Let's start with the beginning:
Season 1: Emma
te may o may not have noticed but the one who always gets seen da Zane is Emma. She is the one who saved Zane, she is the mermaid that Zane saw twice (during his saving and with her red hair) and in the finale she told dr. Denman to go home while Cleo and Rikki just walked away.
Season 2: Cleo
This is not rocket science. The main villain of this season existed da the cause of the Amore triangolo between Cleo, Lewis and Charlotte. Cleo was also the one who first discovered her advanced power and the first to control it. She is the first one to get attacked da Charlotte. In fact, she is the one who drives carlotta, charlotte insane to the point where she wants to take the trio's power; just for revenge!
Season 3: Rikki
This is just pointing out the obvious but Rikki is the one that season 3 is about. She is the only mermaid who has a obvious connection to the Moon Pool and the strange happenings. She is also the first one to get taken da the water tentacle. She is the first one to gain the water tentacle's trust.

So tell me: what is your opinion about this? Do te think it's just a coincidence? Sound off in a commento o commenti below.