First off, as with most anime, don't expect this to be 100% true to the manga.
It's six episodes, so you have to realize it will only follow the general plot of its predecessor.
That being said, this anime was short (again, six episodes) and sweet. It has a good walking phase, and a realistic feel to it.
Emotions aren’t exaggerated at all. Confessing your love for someone isn’t an easy thing to do, and it takes the main character, Seto, two years before he actually speaks up to the girl he likes.
** Spoiler Alert!!! click to hide or show**
He isn't even aware of it when it suddenly slips out of his mouth
Unlike other anime, the main characters don’t end up together in a snap. There are difficult situations, and it's actually a bit difficult to predict who ends up with whom.
** Spoiler Alert!!! click to hide or show**
Seto likes both his childhood friend and his new classmate, and decides to choose Itsuki. But then Itsuki dumps him and says "go for Iori!" You really have to keep guessing until the end.
The animation is much better than you'd expect. The pale colors render a realistic feel. The background layouts, especially the cityscapes, are nicely done. Lighting and shading are used well.
The music gets an average score. It's very generic and fades easily into the background so you hardly know it's there sometimes.
The opening and ending theme songs aren't the best. Easily forgettable.
Overall, I thought I''s Pure was wonderful overall. The short six episodes have a certain nostalgic feel to them--you may even cry a little. The same sorts of things that the characters experience may happen or may have already happened to you.