Nekoin has the appearance of a pink, cat-shaped coin, with a cat face on both sides. It has two dark red eyes and little violet eyelashes that stick out a little when viewed from the side.
It is constantly on the move and spins around quickly. It's hard to catch it as it travels around randomly. Using the Stoplight or the Bicycle when trying to catch it is highly recommended. It shows a normal reaction to the Cat and the Knife effects.
- It is the only Yume Nikki character on the front page of KIKIYAMA's website other than Madotsuki herself.
- The Cat effect references the "Maneki-neko" figure, a Japanese talisman supposed to bring good luck and fortune. Nekoin's appearance resembling a coin ties into this, as not only were Maneki-neko often depicted holding a gold coin, but they were also used as coin banks quite often. On top of that, tiny coin offerings were sometimes left near the Maneki-Neko as a request for good luck, fortune, or for wish fulfillment.
- Its design of a spinning coin may also be a reference to the spinning coins of the Super Mario series.
- The cute and simple design and her general shape may also be inspired by the popular Sanrio mascots, such as Hello Kitty. Hello Kitty resembles the Maneki-Neko and was inspired by the figure.