Tōshōgū Shrine, the burial place of Tokugawa Ieyasu, the founder of the Tokugawa shogunate, is the most popular tourist attraction in Nikkō, Japan. It's famous for its elaborate architecture, but also known for its carved details.

One of the most notable carvings is the Nemuri-neko, or the Sleeping Cat, at the entrance to the okumiya (rear shrine) where Ieyasu's remains are housed. The carving is attributed to Hidari Jingorō, a legendary 17th-century artist who may or may not have been a real person.  Although it is less than 8 inches in size, the Nemuri-neko has a few notable features.

For one, cats are rarely depicted in reliefs in shrines and temples, while sacred animals such as the crane, turtle, tiger, dragon and phoenix are commonly found. This is one of the few cases in which a cat is depicted in early Edo-period religious sculpture.

On the other side of the Sleeping Cat is a carving pair of sparrows, though cats are normally supposed to prey on them. This depiction is believed to symbolize peace, as sparrows can live freely when cats are asleep. The cat being able to sleep without staying alert also means that its environment is safe and peaceful.

Some, however, believe that it’s not fully asleep. Legend has it that the cat's eyes are only half-closed. Its pose does suggest that it may be actually staying alert, so that unclean creatures such as rats cannot enter the sacred place.

In June 2016, the Nemuri-neko was temporarily removed from the shrine to undergo restoration work. It returned to its original place five months later, and to the visitors’ surprise, its eyes were visibly half-closed, almost confirming the legend. As it later turned out, it was because of accidental mispainting during its restoration. Immediately after the story of its half-open eyes became public, the Sleeping Cat was repainted so that its eyes are shut once more.