I can see why folks wouldn’t like the main characters, but I just wouldn’t take them too seriously. It’s pretty clear from the get-go that none of these guys should be taken as role models for real life behaviour. Same goes for the moral lessons: probably shouldn’t be practiced irl, but works well for the purposes of this story. Once you’ve gotten all of that out of the way, you just get an absolutely hilarious (and honestly pretty cute) dynamic between the two leads.
Koharu’s goofy, extremely open and kinda has her head in the clouds, but her sincerity in everything she does is what rounds her out as a character. Kanzaki’s one heck of a tsundere, and that never really changes, but he’s easy to read and his personality bounces off Koharu’s in a really fun way. It takes a while before they start going out, but I personally never felt like it was a drag before or after that point, since it was for the sake of really expanding both of their characters before getting to the climax.
Hilarious dialogue, charming characterisation, and cute art to boot. It’s a nice palate cleanser and a great romcom.