Six of Brendell's specimens were distinguished from its initial classification of Caccothryptus testudo due to distinct genital structures.

The species was named for Hiromu Arakawa, the creator of manga series Fullmetal Alchemist.

[2] A group of Caccothryptus specimens were collected in 1983 in Kathmandu, Nepal by Martin J. D. Brendell, curator of Coleoptera Department of Entomology at the Natural History Museum, London.

C. arakawae has an elongated oval body, brown in colour except for reddish tibia and long, white setae, which are distributed across both the upper and lower sides of the beetle.

The beetle's head, smooth and punctured, is slightly retracted into its pronotum, and features eleven-segment antennae.