look man, you can TRY and put the 20 year age gap in the back of your mind as much as you want, but this manga will remind you of it literally every couple of seconds.
the main guy (who is 45-46) is CONSTANTLY commenting on his own old age, whether out loud or with inner monologue. he calls himself a creepy old man and constantly talks about how old and out of touch he is. his age constantly comes up in conversation or as a gag (he doesnt know how to use a phone, male menopause, hurting himself doing very small motions). like the manga bashes in you the face that this dude is OLD, HES F**KING OLD, HES A CREEPY OLD GUY.
its then impossible to ignore that they are trying to set up a relationship with him and a 24-25 year old woman and make it seem like...its not weird? because they also comment on her YOUNG age. HE comments on it. the manga jumps through hoops to show you the goddamn age difference. hell, the two characters initially met when he was in his late 30s and she was 16.
the manga is creating this problem it didnt need to create.
the dude being 45 doesn't even matter to the story other than the fact that they like to make jokes about it. he doesn't "act" like a 45 year old other than the fact that he works a job that sucks. i get that there is no specified way for a 45 year old to act, but i feel like in storytelling, it should mean SOMETHING. the age should come with some sort of wisdom that he can pass down, which the manga plays with sometimes, but i honestly think its entirely by accident.
also, im sorry, but the fact that the only thing these two have in common is that they smoke just makes them come off as extremely boring.
going back to the age thing, the story likes to play with scenarios where one of the characters will have to quit smoking, which means that....they wont be able to meet up anymore. BUT WHY?! i dont understand this at all. they made a big deal out of mr. old man getting a smartphone, but they have done nothing with it. he didnt exchange contact info with the woman...or anyone. you are a grown ass, 45 year old man, if you want to be friends just ask her for the contact info and stop shaking in your boots and pissing your pants about trying to make friends with someone you are already friends with and see and talk to almost every f**kin day. she even sort of offered her contact info to you and you denied it. WHY?!
maybe thats a cultural thing i just dont understand, but it just drives me insane.
back to how little in common they have...this is honestly kind of a problem with a number of romance manga, where the romance is the only thing that binds two characters together. sometimes the characters will fail to have any sort of personality traits that make them seem like they would have chemistry with each other.
you can sort of forgive this in a lot of these manga, because they a lot of them deal with younger people, like in high school, and sometimes, shit is just shallow. and thats FINE. sometimes, the shallow leads to them learning about each other and growing as people.
you and i are polar opposites partially suffers from the issue i described. the main male lead has NO personality. no likes. no real interests. he is barely a character. he only exists as a love interest and the manga doesnt really do much to ever change that perception. the end result of this is that the side characters/couples all end up being WAY more interesting to follow than the main couple, despite the main female lead being the best character in the manga. she's basically dating a plank of wood.
kono oto tomare, my favorite manga and one that ISNT a romance focused story, does really well in this regard. each individual character FEELS like a person. we get to understand their likes, their personalities, how they interact with other people and how they react to certain things independent of their relationships with their crush. it makes it so that when the romantic moments do happen, it feels deeper and more satisfying because then we can understand why the characters like each other.
smoking behind the supermarket with you falls into the first category, where the characters barely exist out of each other, but unlike you and i are polar opposites, the side characters are also pretty flat and in some cases, completely unnecessary.
im not really gonna talk about her much, but they introduced a new side character whose thing is that...shes obsessed with the main female lead and thats it. she's yawnville boring. i actually now skip her dialogue/chapters because she adds nothing to the story that was already there other than to be another character who hypes up the main male lead.
anyways, i saw a lot of people really hyping up this series. i even saw someone say something like "i dont even like slice of life, but this one is good" and...im sorry, that person must just be incredibly shallow. the premise starts off pretty decently, even if the age gap is weird from day one, but it just runs itself into the ground and the characters become so annoying because they refuse to communicate despite being adults. these people communicate less than children.
i will say that one good thing this series does is the way the artists draws/depicts older woman (like 40+ women). first of all, they tend to look like they belong in hellsing in that they have integra vibes, so they are automatically cool. but these older women are also given romance subplots which hit WAY harder than the main story (well one of them does, the other is the same age gap as the main couple, just reverse the roles). one of the smaller subplots is about a woman who is 50+ who has a crush on another woman who is 50+. why cant we get more of THAT because thats way more interesting than the bullshit we do get.