The reemergence of Hikari from the depths of the sea after five years might not, in itself, be a massive surprise - however, the fact that he hasn't aged a day since the Ofunehiki all those years previously is a decidedly larger shock to the system.
As a result, this week's episode is really all about dealing with the psychological fallout from that shock - although Hikari seems to be in high spirits and taking everything in his stride as he meets old friends and finds them desperate to help him catch up on everything that he's missed, in truth he's terrified by all of the change that he sees everywhere around him and wants only to shrink from it. This is, of course, exacerbated by his final memories of Manaka from that night, and his concerns about what fate may have befallen her.
Meanwhile, we see two very different reactions to Hikari's return from Miuna and Chisaki. In the former's case, she's quietly thrilled that the boy she fell for has returned, and what's more than she's now the same age as him; on the other hand, Chisaki is so scared by how Hikari might perceive her older self that she daren't even visit her old returning friend. Ultimately, both characters inadvertently come to realise their own unique brands of selfishness - Miuna comes to understand Hikari's terror at being the only one stood still in a hugely changed world, while Chisaki's worries are assuaged somewhat when she does finally meet Hikari. For his part, it's meeting Chisaki that finally gives Hikari the confidence to step forth and embrace his new present, perhaps unaware of the feeling of others swirling around him.
Having done a good job of setting up its post-time skip world last week, this latest instalment of Nagi no Asukara absolutely nailed its tone and content - Chisaki and Miuna's contrasting attitudes, coupled with Hikari's false bravado, all made for fascinating character studies in their own right, and once they were all brought together the perfectly delivered emotional fireworks which resulted were truly affecting. It seems as if this series has plenty going for it to sustain its second half, and from being a series that I've quietly enjoyed throughout it feels like Nagi no Asukara is suddenly reaching into the stratosphere with its ideas and story-telling.