Now that Hikari has recovered somewhat both physically and mentally from the situation that has confronted him since reawakening, it's time to head back to school, a return which puts him amongst both strange and familiar faces.
Not that Hikari seems to mind not knowing most of his classmates - in fact, he revels in playing up to his role as their senior as they bombard him with questions which he does little more than play the fool in response to. Hikari's return also means that he's now sharing a class with both Miuna and Sayu, although only one of them seems to be particularly happy to see him back in their midst.
One thing Hikari is missing upon his return to education is a school uniform - something which he seems strangely against owning for reasons that we never quite fully get a handle on. However, Akari is having none of this, and thus sends Hikari and Miuna into the city to have him fitted out for a new uniform - a trip which ultimately sees Sayu joining them. Again, Sayu isn't exactly thrilled about this invite, and it soon becomes clear why as she's treated as little more than a third wheel as Hikari and Miuna chatter and goof around - this eventually comes to a head and all spills out into a heated argument, with Sayu feeling bitter that Kaname hasn't returned while Miuna once again seems to have gotten whatever she wants in her life. The aftermath of this sees Miuna leaving alone while Hikari is left to try and escort Sayu home - having figured out where Miuna may have gone to let off steam however, he catches up with her only for fate to deliver another surprising twist in Miuna's life.
I'll openly admit that I can't quite get my head around the revelation regarding Miuna, which means that either I've forgotten something important or this is foreshadowing of some more widespread future revelations - either way, this is but a drop of confusion in another ocean of great drama, that managed to make the most of some relatively minor drama to reinforce its characters and their feelings in an affecting way that was enjoyable and occasionally touching to watch. It's another positive for what has been a fantastic second half of the series for Nagi no Asukara thus far, and it still seems to have plenty up its sleeve to continue in a similar vein as the show continues.