The phrase that Homer used to describe the sea is typically translated into English as "wine-dark". I don't speak Japanese, but would be curious to know if the author here is translating the phrase from English or the original Greek.
I keep expecting some bizarre horror thing to happen with the Tsuchinokos. First they both got swarmed by them, and then the freaky merging from this chapter
On the panel after he wipes her face, the side that wasn't wiped is darker and has cross-hatching, while the side that was wiped has only the regular hatching associated with blushes.