Where could it go? Hmmm.. Once Keitaro opens up, Tsuruko decides that maybe stress relief is needed.
Or maybe a different venue... say a family dojo? If going that route, they could agree to put him up for a specified time, agree to silence on the identity, and as a reward, agree to buy any one sketch he made of their dojo, and further agree it is not to be sold, but revert to him, should they ever tire of it.... and use *that* to girnd the face of the ass in the dirt with.
Since he likes to draw she offers to be a model as an outlet. How MUCH of a model can be left open for a while. She gets him to draw her on the promise that she or her family would never sell it. See the hijinks that forms when she placed a framed and signed drawing of herself in their room for Motoko to see, but not telling her where it came from.
If it is *that* type of drawing, it could be a private rendition specifically as a gift to her husband... I think she is married in this story. Maybe not.
But if the girls, or specifically Motoko, find it, I could see them searching for the perpetrator of such a crime by grabbing every person in the district and shaking them for information.
Note though, this type of plot may well not work, simply from the standpoint that isn't this version of the master artist supposed to be famous specifically for the scenery arts, not people? Here is the quote.
His work includes landscapes, portraits and still life, mostly in the medium of pencil sketches, however he has been known to try acrylics and oils.â€
Of course, that does not mean he *can't do people, after all, we know he did Shinobu and others in canon... merely he was not known to have sold any under that pen name