Arcanist In Another World - Chapter 83: Letter

Oliver was a shy boy who always got nervous whenever he interacted with girls, which is why he had no girlfriend throughout high school.However, all that changes when his parents decide to help boost his confidence so that he doesn't have any problems interacting with people of the opposite gender in the future.But how do they do that?

At dawn.The light of dawn lingered, hesitant to arrive, while the remnants of the setting sun had long faded into darkness. Within the city shrouded in thin mist, the hidden churches in the shadows, veins clinging to the cracks in walls, the gnawing sounds echoing from the sewers, and the murmuring shadows...A lantern bearer strolled forward.

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

Being able to see into people's past has no real appeal for the teenager this story is about, letting him use it only as amusement and to show off when he was drunk.Never watch into someone's past beyond a superficial level.Never try to find out more than you should.NEVER. EVER. LOOK. INTO. THE. FUTURE.But everything changed the moment he was forced to look into the future, was forced to investigate a murder, and was forced to make the acquaintance of the victim's twin brother('s fists).The more time passed, the more it appeared that the primary reason for this murder wasn't a local problem, but a global one.This single, marred corpse was the beginning of a threat that would shake the world.(MC looses a screw when he enters the prison)BL, first-person view; MC is shuo (perhaps even a reversible couple); love interest falls in love first; both MC and ML are straight, mutual bending, Enemies to Lovers