Event on the First Night Is the second chapter of the manga Ajin: Demi-Human,
illustrated by Gamon Sakurai and written by Tsuina Miura.
This chapter once again starts off in some sort of Ajin research center, as we see a Demi-Human being crushed to death before being resurrected. It is then revealed however to be a video that we are seeing being played on a laptop, and a mysterious figure says "they do such horrible things".
It then cuts back to Kei and Kaito riding on Kai's motorbike on some lonely stretch of road by the forest. Kaito reassures Kei that they won't be noticed and in his head, Kei begins to contemplate what will happen if he is caught, and then says that he does feel pain when he dies, meaning that he can not let himself captured.
The story then cuts to a massive crowd of people outside of Kai's house with a news crew commentating over the scene who interviews one of Kei's friends. The news reporter says that the police will begin a full-on manhunt of the Demi-Human in one day. It is at that moment when Yū Tosaki walks onto the scene along with Izumi Shimomura. Some form of informant for the police tells him that they are fully prepared with tranquilizers to capture Kei, but Yū tells him to not use them at all.
We then shift back to Kei and Kaito on a motorcycle, before Kei tells Kaito that he "needs to pee". Kaito obliges and stops the motor cycle. While Kei is contemplating over what would have if he'd never been hit by the truck, he is jumped by two men, one of which is armed with a baseball bat. It becomes clear that they are looking for the reward for capturing the Demi-Human. Meanwhile, a seemingly random girl witnesses the whole thing from a distance, staying unseen behind some sort of van. It appears that she was possible being sexually assaulted by the two men attacking Kei, due to her ragged clothing and the fact that she says "I can get away now thanks to him".
Kaito comes to save Kei but is struck with a bat by one of the two attackers while Kei is strangled to "death". Yū is then presented to us again, explaining that a demi-human can paralyse anyone with their scream, but this can be easily countered by wearing specialized ear protection. He explains this because on the next page Kei does this exactly, screaming to stop the attackers and protect Kaito. Kei punches one of the attackers before grabbing Kaito and running towards his motorcycle driving away.
Back to the investigation team, the informant asks Tosaki whether they are being misheld information, to which he responds, saying that it isn't that he's hiding anything, but anymore information would be irrelevant and "Ajins are not dangerous. That is for sure". The informant wishes them good luck and they leave the tent, Tosaki saying to Izumi, "We are not human", that officials are different living beings during duties, and that understanding this will allow you to not feel unnecessary emotions.
Cutting back to Kai, we see that he see's his black ghost for the first time, slumping over and looking at the ground. They soon cross some train tracks, driving over it without a problem. The kidnappers however are not far behind him, quickly reaching the same train tracks, however rather than crossing safely, the driver stops on the tracks. When the passenger asks why he is stopping, he says that his body won't move, and we see the black ghost on his shoulders, telling them to die before the train hits their car.
Having saley got away, Kai says that they've probably lost them. Kei begins to contemplate what being an Ajin grants him rather than simply immortality, before we see that the black ghost did indeed survive the train collision, saying I wonder what happened in a broken manner.