School Days... Now, that's nostalgic. I vaguely remember when I first watched the series. At the time, even with the shocking ending, I enjoyed it. In hindsight, this was probably due to my ignorance of what an actual decent anime is, or was at the time. Thinking about the series now, I would rate it as average, perhaps even slightly below-average if we compare it to other series of similar genre.
When I kept thinking about the whole plot, it started majorly both annoy and amaze me. What amazes me is that if you think about it, the whole plot isn't too far from reality. It is plausible to believe that something like that could actually occur. Sure, it wouldn't be an everyday event but it is certainly possible. What annoys me is that the WHOLE story is founded upon lack of common sense; with it, the WHOLE story could have been virtually avoided.
If Makato had just broken up with Kotonoha and started a proper relationship with Sekai, the whole plot would of been shattered, but of course for the sake of the story being able to be continued, some level of common sense had to be sacrificed; this is storytelling, after all. However, the blame doesn't entirely lie with Makato; Sekai, that bitch, didn't really do her fair share of thinking either.
I mean, even if you're helping a friend, you've got to know your boundaries. *sighs* Oh well. I wish they'd made an epilogue to this and not just that "nice boat" scene.