Man, I'm at a loss for words at this route. I guess I'll start with Kotori's character and work my way up.
I can't exactly pinpoint a certain character archetype for Kotori. Yeah, she's the childhood friend, but she genuinely feels like a character rather than an archetype, and that is something I can commend. Her lust for pocket change, her passion for gardening, and her passive friendship with Koutarou make her quite unique compared to the rest of the cast.
Now, her route doesn't exactly develop her character, but it does show a new side of her that explains why she is so distant to Koutarou. The whole message of the route is that life, no matter how insignificant or artificial, is precious and not to be taken lightly. Ever since Kotori's parents died, she spent a great deal of time shutting out her feelings and treating her familiars as tools rather than beings with feelings. These feelings also transfer to her personal life, where she distances herself from both Koutarou and Yoshino in order to not get too attached to them. Koutarou displays a strong affection for Kotori, but she refuses to cross the line she has set for herself, and eventually Koutarou gives up. But Yoshino calls him out, beating him down to the ground both physically and verbally, and criticizes his passive attitude of the situation. Koutarou realizes his faulty thinking, and becomes dedicated to finding and protecting Kotori. But when she finds her, she still refuses to get too attached to him. But Koutarou doesn't give up.
This route also introduces Kagari, a familiar whose goal is the 'salvation' of the Earth. She is the main reason Kotori has her powers, and also why she has refused to commit to any relationship, be it friendly or romantic. She is somewhat drawn to Koutarou, if only because a piece of her ribbon is within him. Her attitude seems to show the malicious intent of her goal, but for the most part, she is shrouded in mystery.
Now to the juicy part: the emotional rollercoaster this plot had. This route easily toyed with my emotions like the molding of clay. Chibimoth's death almost drove me to tears, as did the final scene where Kotori drags Koutarou's dying body to the hospital in one final act of hope. I really have to give credit to Chiwa Saito's performance in this route, not only for the wide range she gave Kotori, but also for her extremely convincing crying scenes. I truly felt bad for Kotori and Chibimoth during this route, and if my heart wasn't made of iron, I doubt I would stop crying for them for a while.
The music also really shined in this route. Many of the songs fit the scenarios they were placed in, although I can barely recall them at the moment. Thank goodness I can listen to them in the gallery, at least.
Not much else I can say about this route, other than that I have a bit more respect for Yoshino now, and I want to know more about the organization Shizuru and Lucia are a part of. But alas, next up is Chihaya, so I'll close by saying that Kotori's route is a fantastic beginning to what is so far a very different and enjoyable take on the Key formula.
Rest in peace, Chibimoth. We will miss you dearly. ;_;7