Is Orin's "Baabuu" a reference to Sankarea's Baabu?

Danbuuri said:

Is Orin's "Baabuu" a reference to Sankarea's Baabu?

Well, can't think of any other cats that would do so.

"Babuu" is a typical baby noise onomatopoeia in Japanese. So I think Rin's trying to get Satori to pay attention to her. Satori's reference to the kitten is a little different from normal, too: she says "赤ちゃん猫", which is literally "baby cat", as opposed to the perhaps more common "子猫" for kitten. That's why Rin responds with baby talk.

I like how the third eye is glaring at Orin too in the last panel.

Pouty Orin going "Goo goo" is so adorable.