I was Caught up in a Hero Summoning, but that World is at Peace (WN) - Chapter 1843: April Fool’s Day Extra Chapter: [Title omitted]

An advertising director is reborn in 1988 Hollywood as an eighteen-year-old blond-haired westerner named Eric Williams.

From then on, he starts writing movie scripts and television songs, becomes skilled in directing every kind of film, wins over all kinds of female celebrities, and takes the road to become a Hollywood legend.

- Description from Novelupdates

A serious accident caused the protagonist’s brain to have an unusual mutation. This changed the brain development that it opened the door to a mysterious universe. Not only he obtained a ‘god-like’ powerful telekinetic control and mental perception, he also had an abnormal analysis and memory capability comparable to super computer. Having such super brain, his rough life began.

Brain development progress 10%…….20%……50%….80%…. …100%

- Description from Novelupdates

Three Days of Happiness is a novel by Sugaru Miaki, also known as Fafoo. It’s a rewritten version of the story originally posted to 2ch.

The premise of the story revolves around a shop where one can sell away the remaining years of their life, and the consequences of doing so.

“I Say A Little Prayer” is a short related story which was posted along with the novel’s release. It spoils some things about the main story, but nothing major.