This show was lambasted at the time (fall 2005), for many reasons. But I always loved it because the leads so clearly seemed to belong together, and there was so little tension in their relationship. That was one of the reasons other people hated it.
It was also my introduction to the incredibly moe voice of long-time ero-game seiyuu Gotou Yuuko, who played Nanami and went on to play Mikuru in Haruhi. Ken's seiyuu, Taniyama Kishou, is now playing Glen, who appears in recent episodes of
Pandora Hearts -- a very different kind of show, but similarly undervalued, at least in Japan.
Recently, I was reminded of this show by the relationship between Yume and Yuuki in
Kanamemo. They are much more lovey-dovey, and both are girls, but the impossibility of them splitting is the same as between Ken and Nanami.
By the way,
Vexx contrasts this with the "wasteland of ero-game conversions." Of course, this
is an
ero-game conversion, too, just not part of the wasteland.