I finished Tsugumi's ending last night. Both the dead end and the "Good" ending. I was absolutely floored by it and was in no state to write or study for finals, but luckily I was able to get by after I had slept on it.
I can't believe this game is still unknown in the US anime/gaming community. People are always clamoring for localizations of visual novels, but I guess what they're really after are big name games with anime tie-ins or eroge or both (Shuffle, etc).
Regarding Tsugumi's ending:
I've got some breathing room so I'm going to play through Sora's branch next.