I just finished Rin's neutral ending, thereby promoting Rin to the first girl for which I've completed all endings. I'm not going to comment on the bad ending, because I find it to be substantially meaningless: it tells us scarcely anything about Hisao or Rin beyond the fact that they split completely and (probably) permanently.

However, I would like to chip in on the debate on which of the good vs neutral ending is better for which of the characters. I've read the various comments posted on the respective re-enactment threads, but I'm posting my comments here to spare myself from having to pick and jump around about the various (inevitable) walls of text in those comment threads.

It's quite obvious that the neutral ending is heart-ripping (and thus bad) for Hisao, whereas the good ending is good for him. The real question is on whether the neutral ending is actually good for Rin or not.

People have remarked that, professionally, NE is better for Rin because she gets the contacts that open up the right roads for a brilliant future artist career.

But is this really better for her?

I think that the questions that should be asked are: is Rin an artist? And does she want to be(come) one?

We know from the experience of Sae's husband as it's told by her and by the teacher (yes, you need to replay and pick both choices when asking them about this if you want both sides) that being an artist means that art becomes more important than anything —even more important than your own life.

Rin is not an artist. I think this is quite clear throughout her whole arc, and in both endings. She has the talent, but she doesn't have the soul. Art is not everything for her, it's just the only thing she (thinks she) can do.

Even more, she paints because this is somehow the only means that she has to express herself and to communicate. She's not good with words, which moreover she perceives as inadequate to express her thoughts and feelings, and yet she realizes (or comes to the realization in both endings) that, even though her art allows her to express herself, it doesn't manage to communicate (the message fails to get through to whoever sees her art).

Parenthetical remark: this is one of the things I really love about KS in general. If you stop to think about what is being described in the story, you can get into some rather deep philosophical topics, such as, in this case, whether it is even possible to communicate (and especially if you take the NE, the answer given in KS is that this is, in fact, impossible: as a general rule, and not just for Rin).

Back to Rin: ultimately, her path is one of forced solitude. She has been essentially alone her whole life, up until meeting Hisao, even though she has been trying to reach out to the rest of the world through her art, and she blames this on herself (“what is wrong with me?” in the GE): she feels this as her real handicap, much more so than her lack of arms.

But let's leave this aside for a moment, and let's go back one step: so Rin is not an artist (in Sae's and Nomiya's sense). And not only she is not one, but (at least while working for the show) she realizes that she's not, and she realizes that to become one she has to sacrifice her (current) life.

And she's not happy about it. This is difficult to confirm because of Hisao's denseness and inability to read her expression, but particularly in the NE it's quite clear that she's following up to her “artist” destiny against her own feelings. She would have much rather had someone (particularly Hisao) by her side, but this would be pointless, since communication is impossible: so she will continue the artist path, eve though this is pointless as well. She lets the events guide her, regardless of what she thinks and feels.

It is said that Rin's path is about answering the question: “can you seize the day?” Well, in her NE, she doesn't. Even though it looks like she's seizing the “opportunity of a lifetime” of becoming a (successful) artist, she isn't: she's just letting everything happen as others have decided (Nomiya, in particular).

I believe this is evident in the NE path itself, but her GE path also confirms this, in at least two key moments. In the GE path, after her quarrel with her teacher, she mentions that «People are doing things I don't ask for and don't want» (emphasis mine). Also, her final question: «What's the word for when it feels inside your heart that everything in the world is all right?»

Rin's GE is good for her, because by abandoning the exhibition she took action for the first time in her life, and seized the last chance she had to not be alone. On the other path, she is not seizing anything, she is being led (by no other than Hisao, moreover) back to her path of forced solitude.

As an extra positive note about her GE, this is the path where Rin discovers she does have other means of expression, even if it's just crying.

TL;DR #1 Rin's Neutral Ending is not good for her, and is in fact the same as answering “No” to the question posed by her path: «Can you seize the day?»

I'm going to spend some additional words (oh yeah, let's make this wall of text longer!) on Rin's art teacher, because it also leads to another point of view about Rin's arc.

In the GE path Nomiya accuses Hisao of not understanding Rin's passion for art, but the truth is that he completely misses the point: he sees Rin's talent, and mistakes her desperation (not being able to do anything else) for passion.

And yes, I do think that Nomiya is just trying to live success vicariously through Rin: “I can't be a true artist because I got scared by my friend's suicide, but I can at least be the one who discovered a true artist”. He doesn't actually care about Rin, he just doesn't want her talent to “go to waste”.

I like to think that Rin's arc is (also) about the left vs the right brain hemisphere, in some interesting and sometimes maybe paradoxical ways.

In a rather superficial but not entirely wrong simplification, the right hemisphere of the brain is the one concerned with sensation. It's the hemisphere of the now, the present without thoughts about the past or the future. The left hemisphere, OTOH, is the hemisphere of logical thought, order, (con)sequentiality, information processing (it's the hemisphere that allows us to read, write, speak, listen, etc).

(I recommend watching Jill Bolte Taylor's stroke of insight, the personal tale of a brain scientist who experienced in first person a stroke that effectively switched off her left hemisphere: very nice and very informative, even though you have to bear some of the hippy stuff she slips into now and then.)

It's pretty obvious that Rin herself is dominated by her right hemisphere: she feels, she lives in the present, she is all about the now, and she finds it much easier and more complete to express herself through pictures rather than language.

By contrast, Hisao is dominated by his left hemisphere: he is constantly thinking about everything, his past, the future, what the present means, he looks for meanings, he wants to define his relationship with Rin, he needs labels to attach to it (friendship? love?)

Nomiya himself, despite his passion for art, is strongly driven by his left hemisphere. He plans, he looks at the future, he tries to get control over life.

And this is one more reason why I think Rin's NE is not that good for Rin herself: in some way, this is the path where Nomiya “becomes” her left hemisphere, Rin is left with nothing else but retreat completely in her right hemisphere, and Hisao remains alone with his thoughts.

By contrast, in the GE, both Hisao and Rin found a better balance within themselves. Hisao starts to learn about “letting go” and living in the present, and Rin starts to get more comfortable with verbal communication.

TL;DR #2 Rin's Good Ending is the only one where both Rin and Hisao reach a better balance between their emotional and logical sides.