Boku wa Tenshi ja Nai yo

After the Great Kanto Earthquake and the World War people are living in difficult times.

The main character, Kitami Ichizou ran away from his wealthy home along with his maid, and took up a job as a novel writer. One day he receives a mysterious letter about an invitation to a dubious secret club called "Masquerade" where he meets Zakuro, the performer there.
On the other hand he also received another letter from Sister Yurina, a nun working at the orphanage which Ichizou donated in the past to. Yurino's letter gradually reveals a troubling confession about her own hidden side.
What will Ichizou do about these two peculiar cases, what point will he end up? Find out and relive the old times in this S&M novel.

(Source: VNDB)