Well, I have in fact played through the visual novel.. So I can say I enjoyed both though I gave the Novel a 10/10 The OVA Follows as best it can the Kaho Path - It changes a few things here a few things there, and it does change the ending a bit to. But if you take the OVA for what it is .. 2 episodes - it is well done for that. The characters are surprisingly well done for 2 episodes - as is the general plot explained surprisingly well for such a short ova. (When it was a far longer Visual novel)And the sound track for the OVA wasn't bad either - Nothing I would go run out and buy, but nothing to scorn either , it fit the mood well , and helped the story along.

All and all I would say this OVA is worth the watch , whether or not you have gone through the visual novel- It can stand on its own and be quite enjoyable (though I recommend you go through both of course)