While pursuing Shiranui, Tama runs inside a delivery truck labeled "Amezon". This is a reference to the online store Amazon.com
Jenny & Isumi insisting that Tama was a cat, is referencing to the feedback the author Kenjiro Hata had received correcting him after he had mistakenly wrote early in the manga that Nagi found Tama while she was in Africa, even though that it is a common fact that tigers don't come from Africa.