Ohten no Mon: Gate of Secrets

Heian period Japan. The Fujiwara family is plotting to seize power at the court, when two maids suddenly go missing from the capital. The emperor fears that it is the work of a demon, and orders Ariwara no Narihira to work with a young man. The boy's name is Sugawara no Michizane.
Sugawara no Michizane, a shut-in student, and Ariwara no Narihira, a Kyoto playboy, are twenty years apart in age. They are different in status and birth, yet work together to solve the mysteries of Kyoto!