This makes a difference.
A lot of comedy and romance titles aren't exactly what people would call "clean", as they were aimed at late teens / early 20s and so include a fair amount of "mature" subject matter and content. For example, "Lucky Star" is generally written off as a massive bit of sugary fluff, but there's a lot of serious matter in the background due to the prospect that the female lead, a high school girl named Konata, may well have inherited the medical condition that killed her mother.
As far as possible suggestions go -
*Azumanga Daioh: This is a slice-of-life series following a group of high school girls and their teachers during the final three years before graduation. It's targeted at a teen audience and so has some moments (like Kimura-sensei being an all-around pervert and creep), but most of the show is based on the daily lives of the involved characters.
*Sweetness & Lightning: The anime is still ongoing, so the ending is still unknown, but what has come out has gotten consistently good reviews. The male lead is a high school math teacher who ends up a single father to a young daughter after his wife is killed in an accident. Between his demanding job and his desperate efforts to care for his girl, a lot of things have fallen by the wayside. As part of it, they're living off of take-out and convenience store fare since he really doesn't have much time to cook. This changes when he discovers that one of his students has dreams of some day owning her own restaurant... and is pretty well being ignored by her status-seeking mother. The lead hires the student on as a cook, giving her valuable experience she can put on a resume and the home life she's so desperate to have while giving him and his daughter at least one healthy, home-cooked meal a day.