First appearance: Volume 2.

Orphaned at a young age when his parents died in an auto accident (a traumatic experience that haunted him for years), he was taken in by Aoe Reiji, “out of kindness.” As a result of Aoe’s charity, he fell in love with the older man. Naoya is well obedient to Aoe, and his brother Kiichi (see below). Naoya is often attributed to a cat (he also adopted a kitten Gyoku), known simply as the 'kitten' when people talk about Reiji's lover.