This chapter left me with a little heartache.
Starting with the first few panels. To me Nazuna has began to resent the things she will never be able to enjoy of a normal life. The normal conversations/interactions people have that vampires do not. Perhaps, I am mistaken and she is just in a foul mood for not eating.
Then we move to the farewell party that isn't anything more than two primary events:
1. Everybody getting some sort of closure. I think it was very ominous there is a farewell party, but it is not quite clear who the farewell party is for.
I mean, sure we get the comment Azami and Susuki are the ones leaving to various places. And possibly Haruka leaving to Hokkkaido as well, but it is a closure for almost every character.
2. We see a weakened Nazuna, likely due to her not feeding properly (maybe related to her not sleeping during the day?) and her kind of apathy towards Kou...
We know the source of her apathy, she tried to keep under control that unquenchable thirst. She wants to feed, but she only want to feed from Kou. We don't know what happened when she spoke to Azami, but she hasn't been receiving any blood we have seen. This is definitely driving her to the edge.
Haruka most likely caught this up, as he noticed how Nazuka slowly drifted away... He has seen Nazuna bored, he experienced it multiple times because she went out with them as she realised she fell for Kou. She must have realised the pain she is going through and that might be what he wants to talk to Kou.
Even the comedic relief moment felt out of place because of the mood of the farewell and the anxiety with Nazuna's behaviour.
I really love this series, but this particular chapter felt like digging your fist in a bowl filled with jelly beans, shoving it in your mouth, realising some arsehole must have dumped a box of earwax flavoured ones in the bowl. It certainly can make you laugh at the moment, but it doesn't wash away the bad taste.