+Anima's underrated. Personally, I believe that this manga comparatively excels in all areas of a shoujo.
I loved how +Anima provided its readers a varying pool of personalities, from the quiet and daydreaming Senri to the childish and feminine Nana. Each character was developed well, not just as an individual, but also as a member of a community. Character relations realistically develops and blossoms beautifully, and the characters themselves go through experiences to learn invaluable morals.
The art is - to sum up in one word - gorgeous. Never is a panel half-assed; even the intentionally comical moments are well-drawn and loved. Expressions on the characters' faces depict well of their emotions and accentuate the situation. Clothing is detailed, and includes tiny details such as hair accessories and unique designs to fit the world of +Anima.
The plot - although there may not be an explicit one, I believe that the actual ongoing plot is the character development. Through each chapter, a lesson is learned and values are gained. Though the plot may be simple, it is the simplicity that makes the manga touching. By utilizing a child's innocence and purity in the manga, the intended message is stronger. The reader sees through the children's eyes, through a different and untainted perspective, lessons learnt don't seem so frivolous.
That leads up to my last point - the overall reading value of +Anima. I think the most important thing gained from reading this manga would be a child's perspective of the world.
I seem to have written a novel. I know this was supposed to be a comment and not a review, but I just feel that this manga deserves a much better rating than it's given. Though its protagonists are children, +Anima can certainly be targeted for older audiences. Its art, story, and characters are all very cute, loving, and heartwarming.