Lilith is introduced, and Devils are confirmed to be a kind of Extraspecies
Some more information on Extraspecies physiology is revealed.
Centaurs are implied to be herbivores, as Centorea said she can only eat fruits and vegetables, and not things like eggs or fish.
Arachnes have lungs in their Spider abdomen, which is also used for breathing. Miia believes that they can breathe through their mouth, but this is yet unconfirmed.
It's shown Rachnera sleeps in Kimihito's attic.
It's revealed Centorea possesses a suit of medieval armor designed for centaurs, a lance, and a shield with a horseshoe emblem on it.
According to Rachnera, Centorea's sandwiches didn't taste like anything. This may due as Centorea's sandwiches is filled with eggs and fish, or for the fact that herbivores like Centorea have twice the amount of taste buds than humans like Kimihito, who already have 20 times the amount of taste buds than carnivores like Rachnera, and as such the others can't taste the subtle differences in the taste of the food that Centorea can; this is causing Centorea can't tell what's her sandwiches taste like. as stated above (About Centorea being a herbivore).
Even though it was stated a few volumes back that Papi is an omnivore, she oddly displays a clear amount of pickiness in what they have for dinner, even demanding to have meat instead, even though she doesn't have a sense of taste, and shouldn't really care about what she's served.