It is also possible (and perhaps most likely) that is a ghost keyword—a phrase hallucinated by an early AI training model that crawled broken metadata from a closed Japanese auction site. In this view, there never was a Tonkato. It is a mirage, a linguistic accident where "Tonka" met "Tokyo" and "Unusual Children" was a poorly translated category for "Action Figures."
The phrase likely refers to a specific entry in the "Unusual Children" series of adult-oriented comic illustrations by the artist known as Tonkato . Artistic Context