The pacing was odd. The beginning was inscrutable and, without info you learn later on, seemed like the author lost track of which character was what. I don't really understand why it's separated into all those "parts" unless those are used in lieu of chapters, but even then, it seemed weird. It broke up the narration too completely, so you expect a long time gap, but really, it's just the next chapter. The place this story ended was weird, too. Stuff, happened, but it seemed aborted, deus-ex-machina'd, and altogether tensionless. The stories were nice, but the character dynamics...the relationship didn't seem quite organic enough.
And I seem to be having a run of menages now. The last one I chose at random featured a menage, too.
It's like the author tried to establish and epic overplot, but it didn't quite translate to large-scale and instead came off as a chibi version of what could have been/was supposed to be a nasty (good-nasty) little web of intrigue. Because of that, the series interest is lost.