Although it wasn't exactly as Tsumugu might have planned it, his feelings for Chisaki are finally out in the open, leaving him little choice but to follow through and explain them to her in detail.
Unfortunately for him, that isn't enough to make Chisaki fall into his arms - far from it in fact, as she rejects him entirely and runs off. But is Chisaki simply lying to herself? It's Kaname (of all people) who tackles her and gives her an outlet for her feelings, which seem to be more predicated upon guilt that she spent all this time awake above the surface while her friends were sleeping, and that as a result she doesn't deserve Tsumugu's love if someone else - i.e. Manaka - should be its true recipient.
In typical Tsumugu style, he doesn't sit and mope in the wake of all this - instead, he focuses his efforts into a plan that might stave off the slow calamity likely to befall the surface while also retrieving Manaka's ability to love. In short, this plan involves organising and carrying out another Ofunehiki, complete with an Ojoshi that is decked out with the necklace that originated from the Red Sea Slug assumed to have been used by Manaka. With Uroko agreeing to help in the matter, Tsumugu succeeds in reuniting those involved in the Ofunehiki five years previously, although with all of our major players in close proximity there were always likely to be some emotionally difficult moments ahead, and it's Kaname and Saya who experience the most intense of these in the wake of some more heartbreak for the former regarding Chisaki.
It's that scene between Kaname and Saya that provides another stand-out moment for this increasingly excellent series - not only was it superb within the confines of this series, it was arguably one of the greatest scenes of its kind I've seen in a long time, even to the point of making fantastic use of the now over-used passing train visual motif. Aside from this, there was still no shortage of strong character moments - Chisaki continues to be a tremendous (if self-destructive) character, this week's episode provided another reminder of Hikari's growth, and Miuna's current path of behaviour is an emotional timebomb waiting to go off. From modest beginnings, Nagi no Asukara has certainly cemented itself as a must-watch show in recent weeks.