The painting is a tribute to the Maneki Neko:

Maneki Neko are one’s of Japan 's most common good luck symbols today, but they were also very popular with the Samurai. These lucky cats originated in the Edo Period, and have continued to grow in popularity since then. One of the most common origin stories of Maneki Neko says a Samurai was sheltering from a storm under a tree when he saw a cat moving its paw as if it was calling him closer. When the Samurai stepped toward the cat, the tree was struck by lightning. The Samurai’s life is saved, and the symbol of the cat waving its paw has beeb considered lucky since then.