In the Anata no Tame nara doko Made mo series:

V.1 - Anata no Tame nara doko Made mo

1-6) Anata no Tame nara doko Made mo
Detective Takachiho Takumi had finally caught the elusive criminal Nanami Youichi after chasing him all the way to a remote island. But what will happen to the pair of them when they accidentally miss the ferry home?

7. Magical Shitsuji (Magical Butler)
   The Butler Tsuruhami tries to turn away a door-to-door salesman, but it won't happen that easly...

8. Non-non
   Ishimaru and Yamada have been friends since the beginning of high school. Yet the closer they get, the more... awkward their friendship becomes!

9. Non-non no Nochi (Non-non the after)
   Will Ishimura and Yamada be able to consume their love?

10. Non-non-non
    Sequel to both "Non-non" and "Non-non no Nochi".

11. Anatadoko Bangai-hen: Naraku Izuko Emaki

V.2 - Naraku Izuko Emaki (Picture Scroll of Somewhere in Hell)

From Yaoi Is Life:
Anata no Tame nara doko Made mo: Heian Style Special

The serious and straight-laced government official of the Capital and Officer in the Right Division of Inner Palace Guards, Takachiho no Takumi, just can't ignore the annoying fake onmyouji, Nanatsumi no Hirokazu, who keeps hitting on him. And now he's forced to work on an accident involving ayakashis! But for the pervert Nanatsumi, he uses every chance he has to turn the situation into a dirty one!