Why does Marnie act so terribly flirtatious toward Anna throughout the movie? If Marnie really wanted to help her out, then making Anna fall in love with her own grandmother would have been the worst possible outcome.
There's signs that Anna is actually standing in for Kazuhiko, Marnie's future husband, in some of their interactions are actually Marnie's memories with him, such as when they go to the silo and she keeps calling Anna by his name. Also, Marnie is a lonely girl, so she might just see her own actions as very friendly and not actually flirtatious. Still a little awkward though.
In the novel at least, there was some implication that that sort of thing was Deliberate Values Dissonance. There were a few clues that Marnie wasn't from Anna's time, and for girls, things like holding hands, hugging, or giving a kiss on the cheek didn't necessarily have the same meaning as today. (In the novel, Anna also acted odd for a child, so that could explain why she didn't think anything of Marnie being rather cuddly towards her.)
I'm pretty convinced that it's Deliberate Values Dissonance in the movie as well. If you read child literature from the early 20th century (which is probably when Marnie was born), you'll find a lot of hugging and kissing, especially between girls, which isn't handled as romantic. Even nowadays, in certain cultures (such as in many Eastern European countries), touching and kissing have much fewer romantic and/or sexual undertones than in most Western societies. (I admittedly don't know about Japan though.)
The Japanese equivalent is Pseudo-Romantic Friendship, which even cites the influence of Western fiction aimed at girls (ex. '"A Little Princess'' and a host of other, lesser-known novels) as an influence. People who read Marnie's actions as flirtatious or were expecting lesbians were watching from a modern Western perspective without taking into account that "normal" or "platonic" encompasses different things depending on the relevant time and place. Even in most Western societies, it's pretty normal for female friends to hug or kiss, especially on arrival or departure, without it spurring assumptions about sexuality.
I take it that Marnie dearly loves her granddaughter and wants to help her, but also the process of coming back from the afterlife apparently involves a lot of amnesia. Marnie doesn't know that Anna is her granddaughter. Even when she's saying goodbye, she only manages "I can't stay", as opposed to "I'm a ghost and I'm going back to the afterlife now." She only has a vague understanding of things. Plus, I don't think any of her interactions are flirtatious per se; she's just so innocent that she doesn't know what might look "flirtatious" from an outside perspective. For instance, she doesn't see dancing as a sign of romantic love; she just sees it as something that her glamorous parents do at parties, and she wants to imitate them. Likewise, the word "love" doesn't have to come with romantic overtones.
What causes Anna to change her outlook on life in the end? Anna's biggest issue is abandonment, and what basically happens is that Marnie abandons her by the end of the movie, despite promising to stay with her. This should have made matters worse for Anna, since she again got left behind by someone she loves and trusts.
Marnie mentions a couple times that Anna disappears and then reappears. It happens once early on when Marnie asks Anna a question, only for her to vanish for sometime before reappearing in the boat; then it happens again at the silo—when Anna falls asleep, she must have vanished and left Marnie alone which is when Kazuhiko showed up. So, Anna forgiving Marnie is only fair at that moment, but more than that, Anna loves Marnie and genuinely doesn't want to stay angry at her one friend who in the end really didn't betray her. Also, Anna knows that Marnie is dead, so she can't cling to her anymore—after that, she learns about their connection and then her foster mother admits that they've been receiving a subsidy for raising her, which was the catalyst for Anna's abandonment issues. Knowing the truth and getting reassurance of her foster family's love, along with gaining a new friend in Sayaka, are what really set Anna back on track.
You have this exactly backwards. Marnie is a ghost (or at least that's how I interpret it). Anna was initially "abandoned" by non-ghost Marie because Marnie was old and she died. But she didn't want to die. In fact, she had so much passionate love for her granddaughter that she came back from the afterlife as a ghost just so she could comfort her. (This process involves getting amnesia, which is why Marnie doesn't simply explain herself from the beginning). When ghost-Marnie leaves at the end, she's not leaving because she wants to. She says "I can't stay". I think this means that she can only maintain her ghost-form for a certain length of time before she gets pulled back into the afterlife. Yeah, it sucks that Marnie can't stick around, but Anna learns that her grandmother truly loves her, which in turn makes her feel loveable. Plus, her foster mother confesses that she's been getting money from the government, and Anna's biggest problem with that wasn't the money itself, but rather the fact that her foster mother was keeping it secret.
The Oiwas' attitude towards Anna's... let's say, less than usual behaviour seems dangerously lenient to me. It's one thing that they understand if a lonely girl going through a tough phase might be grumpy and reserved; it's another to not bat an eyelash when Anna is found sleeping in the grass in dirty clothes late in the evening with one shoe missing! Don't they think it would be reasonable to ask if there is some problem they can help her with? They just seem unnaturally carefree and cheerful through the whole ordeal.
They seem to know what's going on and is just letting her be, after all, what she's doing doesn't seem too out of place for other kids to do in their neighborhood.
I think that's just their natural disposition. They trust that things will turn out alright. They trust that Anna will make good decisions if they just give her space. They figured that she just took a nap; it's not like she was injured or anything. They're a contrast to Anna's foster mother, who always worries. (In fact, they may be deliberately avoiding any expression of worry, figuring that Anna might be sensitive to that sort of thing)
What events led to the real Marnie spending the night at the silo? Marnie tells Anna that the maids never actually locked her up in the silo - they took her home before that because a thunderstorm had started. So how come we find Marnie crouching inside the silo, sobbing, before being rescued by Kazuhiko?
The likely explanation (given that Marnie recalls going up to the silo with Kazuhiko) is that Kazuhiko wanted to break her out of her fear of the silo by getting her to spend time there. He took her there, but it's not completely clear why he left her alone in the silo the whole night. If that was part of his plan to quell her fear, it sounds extremely hard-hearted.
It's possible that they had only intended to spend a little while at the silo, but the storm forced them to spend the whole night there. But then, why would Kazuhiko leave her alone there even for a little while in the middle of a storm?
Anna recollects the older Marnie saying in relation to the silo episode, "I've overcome many frightening things and so will you." So it was probably a deliberate plan between Marnie and Kazuhiko that she should spend the night there alone, but Marnie became frightened part way through when the storm struck.
Maybe the meaning just blew over my head then, but I remember my impression of that scene was Marnie remembering and crying at why her husband had died and him arriving to get her was their ghosts reuniting. I don't remember the details of the scene now though so it could be wrong.
^ No I think you're right. Marnie is terrified of the silo, confides in Kazuhiko about this, and Kazuhiko's plan is to lock her up there and leave her there? That's much too cruel.
My headcannon goes like this: First, the maids and Nan scared Marnie with stories of the silo. Later, the maids tried to scare her even more by dragging her up there, but they got scared of the storm and went home (with Marnie in tow). Later still, Kazuhiko came up with the idea that he and Marnie should go to the silo together to confront her fears, but Marnie backed out when they got to the door. (This part is not specifically depicted, but it would fit with everything else.) Later still, Marnie felt ashamed that she chickened out, and so she went to the silo alone to confront her fears. Unfortunately she got caught in a storm and her fears got the better of her, so she was trapped inside the silo for several hours. Fortunately, Kazuhiko noticed that Marnie was missing, figured out where she had gone, and showed up personally to rescue her from the silo. Many years later, Ghost-Marnie is reliving some of her old memories and fears, and Ana gets the same idea that her grandfather once had: Let's go to the silo together to confront your fears. Along the way, Ghost-Marnie conflates this moment with the memory of when she and Kazuhiko went to the silo together (before she chickened out), so she refers to Ana as "Kazuhiko" for a moment. Ana gets distracted by Sayaka, and by the time she reaches the silo Ghost-Marnie is now reliving a different silo memory, specifically the one where she went to the silo alone and Kazuhiko came to her rescue. This is why she again mistakes Ana for Kazuhiko (for a moment).
How is Anna related to the Oiwas? She calls them Aunt and Uncle, and we know that unlike "Auntie" she is biologically related to them. However since Marnie was an only child, and only had one child herself, and no one knows anything about Anna's father, Anna would have to be related to them through Kazuhiko. This would make sense since he grew up in that area. But if one of the Oiwa's is Kazuhiko's younger sibling wouldn't they already be familiar with Marnie's story and be likely to mention that Anna's grandmother lived there when telling the story of The Marsh House? If they're a distant enough relative that they don't know the story then how is Anna related to them?
Where is it ever stated she's biologically related to them?
It's stated in film that the Oiwas are "Auntie's" sister and brother-in-law respectively. But there is a minor plot hole why nothing is said of anyone from Kazuhiko's family, unless the folks glimpsed in Anna's flashbacks of her grandmother's funeral service, which included a couple of them discussing who would care for Anna, were Kazuhiko's relatives.
She's not biologically related to them. (If she was, they surely would have adopted her after she was first orphaned.) She's only connected to them via her adoptive mother. "Aunt" and "Uncle" are simply the best terms she has for them.
It's been a while sine I've seen the movie, but do the people living on the island know or suspect who Anna is in relation to Marnie? It seems like an astounding coincidence that she just so happens to end up where her White grandmother grew up, if not.
There's no indication that anybody suspects the connection. (Except for the bit where Sayaka thinks that Anna is Marnie.) It's either an astounding coincidence or the work of supernatural forces.
