Kamikaze Explorer was the third game from Clochette I played, and even today it remains in my memory as one of the most well-balanced charage/plotge hybrids I've ever played. I say 'balanced' because most games don't achieve hybridization at all. Most charage are essentially character development, light romance, and SOL with little else. Plotge, on the other hand, often tend to go for 'efficiency' on character development, romance, and SOL (exceptions exist), and true hybridization of the genres has become exceedingly rare in recent years (specifically since the beginning of 2015, we saw a general decline in charage with actual stories and a fall in the overall number of plotge).
Clochette is a company more famous for being full of oppai girls than for its stories... but that is mostly because anyone's first impression on seeing the cast of one of their games is that the heroines are all... large, to say the least. That said, except for a few failures like Amatsu Misora ni, this company has produced nothing but charage/plotge hybrids since it came into existence, with the company having a steady, if not huge, following in Japan and over here.
Kamikaze Explorer is based in a future where much of the world has been sunk under the oceans and technological development has stagnated. However, about twenty years before the story began, large numbers of children began to be born with or display supernatural abilities that came to be labeled as Metis. These abilities generally were based somehow off of the hidden desires of the user, and, in the more well-off countries, it was decided to research them in a humane manner rather than the inhumane one you would usually expect.
The protagonist, Hayase Keiji transfers into a school that is centered on researching and training such individuals (such individuals being labeled as Metis-passers). At the school, he is immediately recruited by the pretending-to-be-arrogant-but-actually-shy ojousama Mishio into Argonaut, a club that seeks to help people in general while also acting to solve Metis-related incidents at the same time. Keiji is something of a genius, driven by his sense of curiosity to the point of obsession, and his current obsession is Metis.
From a purely SOL-romance point of view, this game is pretty sappy. There are a lot of really obvious emotional points, and the ichaicha is heavy-handed... However, in this case, that doesn't come across as a negative... mostly because the ichaicha is usually interspersed with relatively serious moments and plot-related issues.
The plot itself isn't huge in scale, but it is dramatic and shows off perhaps too much of a dark side for the average charage at points. However, for the most part, it is not heavy-handed or excessive. Well, I will say one of the antagonists is a bit creepy/scary, but that just made the game interesting, at least for me.
It needs to be said again, but this game is a hybrid of charage and plotge so those who purely want one or the other should think before playing. Like all the games by this company, the H-scenes are mostly mild... but they are also extremly erotic and relatively plentiful for a game of its length.
Edit: Incidentally Miiko (Mishio) is my waifu. Grab one of the other girls if you want a waifu *snarls viciously*