Word usually written using kana alone

frog

かわず／カワズ only

kajika frog (Buergeria buergeri)

prawn; shrimp; lobster

opossum shrimp (Mysida spp.); mysid

Historical term

Emishi; Ezo; non-Yamato peoples in northern Japan

えぞ only; Historical term

Yezo; Hokkaido, Sakhalin and the Kuril Islands

toad (esp. the Japanese toad, Bufo japonicus)

spiny lobster (esp. Japanese spiny lobster, Panulirus japonicus)

Yezo (northern part of Meiji-era Japan, esp. Hokkaido, but also Sakhalin and the Kuril Islands)

Edo-period realm of the Ainu (as opposed to the Japanese) comprising most of Hokkaido

goby (fish)

yellowfin goby (Acanthogobius flavimanus)

(coin) purse with a metal clasp

arching one's body backwards (like a shrimp)

Kabuki

holding out one or both hands and arching one's body backwards like a shrimp (to represent being overwhelmed by someone's power)