Kiyoshi Gaiden by Pegasus

Despite the infamous reputation the character of Kiyoshi has in the canon game and even more thanks to the scenario Harem, a lot of people have gotten away of Kiyoshi-related stories, but one of the first published scenarios actually depicts a very fun take on the character and his surroundings.

In this scenario, Kiyoshi is abducted by aliens instead of John, and around 1 ending and three placeholders are given in 15 minutes of playtime.

Some people might expect a dream-ish hell hole like in Harem since Kiyoshi is the character that seems is the one that is most expected to abuse the power of the remote like Harem did, and he does in one of the routes, but at the difference of the previous scenario, the author actually acknowledges Kiyoshi's mischievousness and shows empathy for the students that are going to be mind-controlled by him and in an actually funny way. The story ends there on a placeholder, but for what it seems like, it seems that the author planned in Kiyoshi actually learn from his action, but nothing can be said aside from that.

The other routes are less impressive, Kiyoshi becoming Zoey, breaking the remote, and meeting Brad, which seemed to point into ID or PD but it ends too soon as well.

In the other one, Kiyoshi tells John about the remote and they use the possession function of the remote (explained in a conveniently and clever sci-fi way) and also ends soon in a placeholder.

Although the scenario doesn't contain enough content to be considered a story on its own, it offers a lot of great jokes, even some at Kiyoshi himself. In the only ending, the scenario has now he decides to not accept the remote and asks the alien bunny girl to have sex with her instead of proposing interspecies intercourse since the alien can't get data now with Kiyoshi experimenting with the remote, she decides to examine him through his rectal cavity instead.

In general, this scenario is everything that Harem should have been, it has a more human depiction of Kiyoshi showing that a funny story can actually be made around him possessing the remote, and overall offers a good, short blueprint for any people interested in writing a story with him as a protagonist.