Headscratchers / Kubo and the Two Strings

• It's not called "night of the living dead" guys. The "festival" in Kubo is the matsuri. (Trust me, I know. It's a big part of my culture.) The matsuri last for basically all of July, so why does Kameyo specifically say "I got myself all spruced up for the big DAY!"? Sure, they never call it the matsuri (even though that's exactly what it is) or say that it only lasts one day, but still...
• How was Beetle's arrows not falling out of his quiver when he dived and swam in the sea at one point?
• How was the Paper Hanzo able to become its own sentient being even though it turns out Beetle was Hanzo the whole time?
  • Beetle himself said that people don't truly die as long as they are remembered, especially in stories. Hanzo lived on in Kubo's stories even if Hanzo still lived as Hanzo's identity was what is "dead". It is this memory of story Hanzo that lives on in the puppet. The paper Hanzo is merely the receptacle for what remains of Kubo's mom's memories of Hanzo, and may have picked up Beetle's lost memories as well, becoming this "memory Hanzo" that strives to guide and protect his son.
• Why are the sword, breastplate, and helmet placed where they were?
  • Maybe the Moon King put them there after defeating Hanzo? Of course he'd want to make it hard for Sariatu or Kubo to retrieve them and having no idea where they are. It's also worth noting that in stories like mythologies, MacGuffins tend to be conveniently closer for access during treasure hunts or something like that, but there's always some sort of ferocious beast guarding it, but we're not always given reasons as to why things are in their places as they are. One thing with the helmet is possibly that if it was always the bell, then the Moon King might have wanted to taunt Sariatu or Kubo for being fools when they went to Hanzo's fortress in search for it instead thanks to his vision with Kubo, as well as lure Kubo back for their battle.
  • In the "room where Hanzo prepared for his quest to find the armor" that was discovered in his fortress, there are depictions of the Sword and Breastplate in the locations where Kubo found them. This suggests that Hanzo never actually got the chance to retrieve any of the pieces himself before the Moon King stepped in. In fact, by the mention that they met at the Temple of Bones, it sounds like Hanzo met Sariatu on his way to claim the Sword. And considering that Sariatu and her Sisters killed other heroes seeking the armor... These could be the original resting places of those pieces. Maybe whomever made the armor had the pieces guarded by monsters as a test for any heroes who wanted to claim them. The Helmet/bell is the only one that was ever retrieved from its original location before Kubo could get to it.
• Why didn't the Moon King go after/send the Sisters after Sariatu and baby Kubo after they landed on the beach in the opening scene? Surely they had already defeated/held off/cursed Hanzo, and if not, one of them was probably still strong enough to chase them down. They might have been controlling that wave, but they must have seen that wasn't enough.
• The origins of the Sword, Breastplate and Helm are left vague (not important to the central story), but it's odd that such plot devices exist. The Moon King is deeply concerned that a mortal with all three could kill gods. Where did Hanzo find them? There's nothing to suggest mortals have the capability of making such things... is there some other great kami out there who dropped a Deicide Kit on the mortal realm?
  • Maybe a Sun Queen or something like that, given the solar symbolism of the items.
  • I don't think it's ever outright stated that the armor would give a human the power to kill gods. Just power to make the human "a threat" to the Moon King's domain. (Or at least that's what the Moon King thinks. There'd be no threat at all if the armor ended up in the hands of an eccentric collector with no interest in fighting.) Maybe all the deities scattered mystical weapons and artifacts around the world, guarded so only the worthy may wield them, as a way of giving mortals a chance to defend themselves against other deities that become hostile. Maybe there's a set of Moon Armor with a legendary bow and arrows hidden somewhere, in case the Sun Queen ever takes issue with humanity.
• What was Beetle doing on that mountain when he met up with Kubo? For that matter, what does a giant cursed bug do for a living?
  • He could have been seeking things that may be connected with his past, in an attempt to unlock memories. He did describe himself as either a former samurai, or a really bad hoarder when he first met Kubo and Monkey. Maybe he was hoarding samurai stuff connected to Hanzo.

• If Sairatu always had brain damage, then who took care of Kubo as an infant/toddler/young child? Did it just not progress until he was a certain age?