Back Then, I Adored You - Chapter 23

In the waves of steam and machinery, who could achieve extraordinary? In the fogs of history and darkness, who was whispering? I woke up from the realm of mysteries and opened my eyes to the world.

Yo, Hi! I’m Frank, I made a deal with a demon to pay me some money for receiving a guest for a few days every week.
I had no idea about what I have done.
On May 1st, Conan ‘the God of Death’ came to my house. I was forced to let him in and we get involved in a criminal case.
On May 8th, Bruce Wayne ‘Batman’ came to me. I was forced to follow him to fight crime.
On May 16th, Hannibal Lecter, The Silence of the Lambs, came to my home. I can only say that I really can’t stand my guests.

- Description from Novelupdates

Getting the [Boosted Gear] is expected for Issei. What if he gained it a month early and another one as well? Let the Games Begin... IsseiXHarem (if it wasn't, it wouldn't be DXD). Now has a TVTropes page! Getting the [Boosted Gear] is expected for Issei. What if he gained it a month early and another one as well? Let the Games Begin... IsseiXHarem (if it wasn't, it wouldn't be DXD). Now has a TVTropes page!

Bought it right away.