14 sketches10 in colour
The sketchbook.
Tsuki's website has a page called Conceptual Sketches, and a few of the same pencil sketches turned up on X. Here they all are, with the community's colour versions beside them.
The pencil sketches are Tsuki's, from tsukionsol.xyz and Tsuki's X posts. The colour versions are illustrations made by the community from them. They are not records, and nothing here says what a sketch means.