What do you mean by new? Recent? And harem or no harem anime?
Just throwing out high school anime:
Azumanga Daioh: Very cute series with almost entirely female cast, no romance, humor that can be appreciated even by a Westerner and some heartwarming moments.
Cromartie High School: Absolutely insane, still funny.
Ouran High School Host Club: Generally good writing with funny scenes and a likable lead character. Unfortunately it's one of the many 'rich weird hot boys around average intelligent girl' so it might just not appeal and it follows cliches. Were it made later I'd say it has