No "Mairimashita! Iruma-kun" please, for some reason i found it boring as it getting dragged too long without major inputs anymore. They just keep adding more characters, more side quests etc.
This are the examples of my favourites.
https://www.mangago.zone/read-manga/youkai_gakkou_no_sensei_hajimemashita/
https://www.mangago.zone/read-manga/natsume_yuujinchou/
https://www.mangago.zone/read-manga/fukigen_na_mononokean/
https://www.mangago.zone/read-manga/hakai_shin_magu_chan/
https://www.mangago.zone/read-manga/jibaku_shounen_hanako_kun/
I hope these are okay, I couldn't find many sadly
https://www.mangago.zone/read-manga/phantom_busters/ (still ongoing, it's really funny)
https://www.mangago.zone/read-manga/tougen_anki/ (I haven't read it but I think it fits what you want to read)
https://www.mangago.zone/read-manga/as_miss_beelzebub_likes/
Any straight or non-romance manga that cute, fluffy, comedy, or 4-koma style like this? I really love this series and it's anime version. It's cute that can make me blush. Kinda underated.
THIS TRUYEN IS SO FUNNY PLEASE READ https://www.mangago.zone/read-manga/badluck/
I hate how they portray Touka-san aka the mistress as someone cool. The audacity to steal someone husband and act like a proper guardian to fl. What is wrong getting divorced or break up properly with your partner if you doesn't love them anymore? Why must you cheat? Cheaters are trash.
Her fiance is the chemistry teacher? I don't think he have another woman or what. Maybe visiting his late wife/lover grave. I hate story where the couple separate and they be happy with other people at the end. It's realistic but i still hate it in fiction.