Okay, here's a newer idea that I don't think I've posted before.

Death Note

Guro Note? Fun Note? Fun With Death Note? Whatever...

TL;DR:
A guy with a Death Note goes around having fun by using it to make people around do things like give him a blowjob or cut their own throat just for his fun, and the fact that any usage must end up with a person dying he sees only as a limitation meaning he only has one chance for each person. So if it's someone special like a girl he loves or his sister, it only means he wants to come up with a funner way to use it than a mere blowjob, and having a challenge like that is a fun on its own.
Long version:
There is a kind of stories where it is basically the protagonist going around having fun in any way they want. Then either they're good in hiding from police, or maybe it is set in a world where raping and killing lolis right at the playground on their moms' eyes is totally causal. Or sometimes a protagonist of such a story would have a superpower like to stop time or make everyone believe what they say or make anything they do to be viewed as normal, or a power of mind control, that kind of thing. So this story is something like that, only the power has limitations - you can make a girl you like give you a blowjob, but she must end up dead.
Anyway, the story begins when the protagonist, might be a guy or a girl actually, but let's stick with a guy for now. So the protagonist gets a Death Note just like in the manga and anime by the same name (I have to admit though that I haven't actually read or watched either, but I have a general idea). Our protagonist is not Yagami Light though and is not obsessed with an idea of making the world better by killing off criminals or anything like that. He might use it to get rid of the guys who bully him at school, perhaps while testing what the note is capable of, so basically killing two birds with one stone. And as he kills one of them in some hilarious way, he starts seeing the Death Note as a mean to create fun and hilarious situations, the affected person having to ended up dead only means to the protagonist that he can only use it not more than once on each person. So, like, he wants a blowjob from a girl he likes, but the only way to use a Death Note to get it is to write her suffocating on his dick. And he only doesn't do so because he thinks it would be a waste to use his only chance with the girl he likes on a mere blowjob. Instead he starts with small things like that from just random attractive girls around, like he comes to a restaurant, maybe actually on a date with his actually beloved girlfriend, sees and attractive waitress, learns her name from a badge, and writes her dying by suffocating on his dick. Or maybe he sits on a boring lecture at school, looks around for an attractive female classmate and writes down that she will be called to answer at the blackboard, take a knife with her (for that she must have a knife on her though... so maybe he knew she had, or she had scissors, or maybe he had actually wrote it all in advance, so anyway...), turn to the class and cut her throat with a broad happy smile (maybe say something like "I'm going first, see you on the other side, guys"), and he does all that to her just because he thinks it would be fun. Another thing he can do is make a pop-idol girl he is a fan of kill herself live on TV. But for special cases like his favorite idol, his beloved girlfriend, his sister and such, while he doesn't hesitate to kill them off for fun, he saves them for later until he comes up with really special and fun ways for them to go, because he only has one chance for each and he doesn't want to waste it for something that can be done to any other random girl. Well, I say girl, but of course you can use this idea to write about a girl killing off guys or a guy killing off other guys or whatever is down your alley.
Speaking of which, I don't imagine a shinigami accompanying the protagonist, but you can have one if you want. The original death note rules say that while there are both male and female shinigami, they can't have sex, be it with humans or each other, but for this story this surely can be ignored. So you might as well have a sexy loli with demon wings as a shinigami who would also not wear any clothes because people except the protagonist don't see her anyway. Though thinking of it, having a sexy naked loli with demon wings always accompany the main character but never have sex with him because her kind is not interested in sex, is fun on its own. Maybe she has fun teasing him or maybe she is totally uninterested and just ignores him staring at her. Anyway, I imagine, if there is a shinigami character in the first place, then they are probably a trickster character who have given the Death Note to our protagonist to see what fun and hilarious things would come out of that.
Now, the protagonist just wants to have fun and is totally unconcerned about death of the people he uses the Note on. Even if it's his beloved girlfriend or sister, their death only means to him that he can only use the Note no more then once on each of them. Which creates a challenge of coming up with a most fun way to use it, and challenges are fun by themselves! Such an attitude is why he was chosen by that shinigami in the first place.
What for the word though, it is not one of those where everyone would see death as casual and mundane and where you can come up to a person and ask if you can kill them and they'll say "sure" or maybe you don't even have to ask. In such a world you wouldn't need a Death Note in the first place. On the other hand, in this world they probably don't dwell much on death either. Nobody wants to die and they would probably be sad for a day or two if someone close to them died, but on the other hand when a girl comes to the blackboard and cuts her throat in front of the whole class, the next day everyone will be talking of how fun and cool it was and remembering her last words that she'll be waiting for them they'll laugh over who might be next to kill themselves (while each won't want to do that, they'll laugh picturing others in the role). Something like that. Or at least that's how I imagine it.
Also, the rules of the Death Note in this world might include something like any death happening by it will be viewed as natural, well not natural as in of old age, but no one will see anything suspicious about it, it just can not come to anyone's mind that someone might be behind it. So the protagonist can use the Death Note as recklessly as they want, no L would come for his head. Even if he makes all the girls in his class have sex with him right on the lessons (speaking of which, any such an action will also be viewed as not suspicious, as in they'll think it's crazy, but they'll all be sure it was the girls' own will, including those very girls of course, they'll also believe they're acting of their own will) and kill themselves in the process, and the people around won't consider that the protagonist might be somehow involved, they might even joke like "you're pretty popular with suiciders, lol" or "man, it seems sex with you is pretty deadly, lol" all in good fun.
Also in those rules it said that the death should occur something like no more than 20 with something days from when it is written, then there was also a way to cheat it by writing death of disease without specifying time of death and with picking a disease that takes more time to develop than those 20 with something days. For this story I'd say either the protagonist saves long plans like this for his girlfriend / sister and the like (for example, make his sister into his sex slave for two weeks before she finally dies), or the limit is actually less, like 24 or 48 hours, just so that the protagonist must be creative enough to have enough fun even with such limited time per person (especially his girlfriend and sister from whom he wants to get the most fun possible). I'm thinking the long things lasting 20+ days would drag the story while the more immediate action might be more fun (also it only means the effect of the Death Note itself is limited to 24 or 48 hours, but the protagonist might have plans and preparations ahead of time, like buying a chainsaw before writing his sister killing herself with it).