This was one of the most unique stories that I've had the privileged of witnessing in a long time. This was a cross between harem, mystery, Romance, and sport (if you consider scuba diving a sport that is).
Story:
The story starts out with a class trip down to some tropical islands where our lead protagonist meets a girl who blames him for killing her mom. One thing leads to another and the next thing he knows he's learning how to scuba dive with some long lost, and apparently forgotten friends. Now this story really has two stages to it. It starts off with the very technical stuff: setting character dynamics, relationships, and intro into the main storyline, as well as all the tech of scuba diving. Being a scuba diver, seeing everything that i learned put into this story, and extremely accurate i might add, was really cool. But for those who aren't into that type of stuff this can seem kind of boring.
Then the story cranks it up to the real mystery and plot. Now without giving anything away, this is when the characters really start to change and grow, and for most people this is when it starts to get good.
This story does have it back draws though. The story seems to pull in every which way up until the very end, which can make the story exciting but also confusing as well. But the main thing was the fan service that was in here. While not being overwhelming, there still was a great deal that didn't seem to have any point for the story except being there, as well as also taking away from the pure romance of the story.

In the end, this was one of the most enjoying mangas that I've read so far. It had great and compelling characters that stuck with you, even if they do drive you crazy at times. It also had a plot taht made just want to keep on reading up until the very end. I definitely recommend this for anyone who is looking for a good fun read.