
According to this tweet by Usazaki, this one shot was from the issue of Shounen Jump for the week of Dec 20, 2020.
https://twitter.com/uszksr/status/1340698115825799171?s=20
Magazines often have one shots that may later become full on series if the readers took enough interest in it. In fact, Usazaki's old work Asagaya Geijutu Koukou Eizouka e Youkoso(the other one listed under the "Other manga by the same author(s)" section) was the one shot that preceded Act-Age!
Iirc she collaborated with the writer at 18 years old and when Act-Age came out she was 22 which is VERY young for an author to debut and in a magazine as prestigious as Jump nonetheless! Being a female co-author for a series that is in a predominantly male industry makes her feat so much more incredible. It's unfortunate her debut series was put to a stop because of the writer....Thankfully JP fans were super supportive of her when the incident happened, but until this one shot came out she hasn't done any manga-related work since then.
Depending on how well the JP audience liked this one shot, give it a few years and there is a possibility for it to become a serialized series as well.

I wanted to point some things out with the title and the author's name which were neat little details.
First off, 炎上する is a term used similar to "flaming" or "exposing" people (most often) on social media in english. It's also literal meaning is "to go up in flames" (which is metaphorical to what happens to a person's reputation afterwards), and in the story, the house really did literally go up in flames. MC's goal is to prove (expose) the second wife was responsible for the fire.
Secondly, not sure if this is the author's only work, but "moyashi" sounds like 燃やし (from 燃やす "moyasu"; moyashi is not an actual form of the word) which is another word for "to burn". it could very well just be a coincidence but if it is, it's one that works in the author's advantage

While it's satisfying to see haru win and it's clever how she used all her abilities to get the achievement, i kind of wish they were able to win because of their actual skills in the game itself rather than distract the other players so they can't perform at their best. But given the lack of time they have to practice and other things, it's understandable but it is a little frustrating

the missing chapters are being added now. they are listed as ch 180-181 (for now). these (along with several more that have yet to be added) happened between the chapters listed as 175-176. while reading them after the events that happened ch 176 onwards didnt flow badly, the sudden change from ch 175 to 176 was really confusing so it would be best to follow the order that's listed in the raws someone posted earlier

the series of panels in the new chapters is a little off still. it'll make more sense if you look at the raws and then come back for the dialogue translation.
just reiterating for people, start from ch 163 on this site (taken from ritu in the comments. ty for sharing)
https://www.cocomanhua.com/12958/

I really enjoyed this story but the ending was really confusing and i can't see why they had to go that way. there is someone in the comments bellow that theorized what happened in an easier to understand way so if you also don't understand it, scroll down a bit. the fact they called the two places as separate worlds instead of different points of time really threw me off. and also now they are reunited what's going to happen? can the water god become a human? if he does, will it be like before where he just assumes the form of a human, or can he become a real human and grow old with her? i think it would have been a lot better if they had made them actually separate worlds and when the water god passed over he became a normal human without powers, since the other gods said if the water god "dies" (becomes too weak) they'll be reborn completely without memories of their "past life". if he became a human, separated from what makes him a water god, it could be possible for a new water god to be born and maintain balance in the other world. this also brings up another problem. if the water god is now in the girl's world, who will fill the imbalance in the other world now there is no water god there? there's a lot of plot holes in this ending which ruined the experience.
the first thing they didn't address is what happened to that crazy woman? after we were introduced to kurose, she never appeared again. it would have been nice to see what happened to her and it would be even better if she suffered some kind of karma.
the second thing is, the guy with the scar across his face says he'd try to make asahi choose him and we never got a conclusion to that. he literally did nothing about it afterwards, and it would have been nice to see him give up on that idea or something like that.
the third thing i want to mention is more of something that would have been nice than something that was left unanswered, but toyokami having a change of heart. when the water god as a droplet was in the underworld, the other gods were also there at the same time so him helping the water god could have been because of pressure from all the other gods. the fact he wasn't hostile was a sign of change, but it would have been nice if we got something about why he acted the way he did since earlier kurose recalled toyokami kept asking if he was having fun. instead of chaos, maybe he just wanted to have friends or something like that. since gods live for a long time, that would have been nice to see so that toyokami realizes what he was really trying to achieve and not make the same mistake in the future. kurose's compassion for him as they left gave some hope that he's not a straight up bad guy, but they didn't show that he actually was not a bad guy in the end very well.

At the moment this is really the last chapter but the author is working on a fan book right now that might offer more information (whether or not it gets uploaded is a different story). I hope the author considers a sequel where Hanae regains his abilities, even at a weaker state, but by his own ability now. If his father could see them, and he can at least still see fuzzy, then there's hope that he can strengthen that skill to increase the range. Maybe there'll be a sequel after a time skip since hanae suggested he'll come back "whether we graduate high school, become adults, or take different paths in life".

one thing i noticed is that the title (in JP) is an anagram for "i love you". the specific word is used for really really deep love so it's rarely used in real life (like on weddings or anniversaries but often people don't because of reasons im about to mention) otherwise it sounds awkward and heavy; which parallels the way aioi falling in love with criminals because they're criminals is unusual.
haven't figured out what the title "i tell c" means but c is probably referring to "criminal". maybe by "tell" it's referring to telling the criminal about her feelings of love? its just a theory
edit: just wanted to clarify yes, you may see 愛してる (aishiteru) in a lot of songs or other manga or anime, but the language they use in fiction media is different from how people speak in real life so they aren't an accurate representation of how often some words are used.
as with many isekai manga, this one is also based off of a novel. i can't find it online for free so i don't know how much more if at all the thing about women having potential to use magic was expressed in the novel. all we can do is hope the novel did justice to the story because imo there was a lot of potential!
one big thing i don't understand is that if women born with those marks can potentially use magic as they are, rather than hide the fact they can why don't they develop magic curriculum so to teach women how to use their innate magic ability? i can understand hiding the fact that the boys that are born have greater magic power so that nobles don't try to take advantage of that and try to "breed" stronger offspring, but wouldn't teaching women how to use their magic to protect themselves be the safest way? if they had hinted at releasing this information AFTER finding out how other women besides the mc can harness their magic then it would have been fine, but it seemed like they weren't planning to tell anyone and it leaves a sour taste in my mouth
Yes, it just ends up burying that fact women can use magic. It doesn't stop the discrimination.