It's a gender-switched reverse harem. I'm misusing terminonology, but it is. "Harem" = male protagonist surrounded by girls. "Reverse harem" = female protagonist surrounded by boys... but certain things follow on from that. Harem anime traditionally have boobs, fanservice and implausible otaku-pandering. (Bland cardboard hero is loved unconditionally by every girl in the world, apparently because they've been hypnotised by the genre.) Reverse-harem anime are equally likely to have cardboard protagonists... but they'll have completely different patterns of fanservice, relationships and stereotypes (especially the classical pretty boy categories). The protagonist will often take a pseudo-maternal role, managing or otherwise looking after her attractive but sometimes not-too-bright boys.
The latter is this show, except that the girls are clever and our male protagonist (Yu Ayase) is rubbish at everything except cooking, housekeeping and shepherding people. Functionally, he's their mum. (Note that he's defined by his relationship with his late superstar mother. She was brilliant at everything. He's useless.)
The Mikadono sisters are tough, intelligent and manly. They're geniuses. 1. KAZUKI MIKADONO (statuesque, dashing, purple hair) is an actress who specialises in male roles and even offstage is always Prince Charming. Her scenes with Yu can be hysterical, because Kazuki and Yu are such a good fit when gravitating to their gender-switched roles, even when they're trying not to. 2. NIKO MIKADONO (short, grumpy, ginger hair) talks like a thug and is a martial arts champion. 3. MIWA MIKADONO (green-haired gremlin) is a grimacing social incompetent who's determined to be a shogi grandmaster and cares about nothing else.
This is great. The sisters are all terrible people, but completely different. Sometimes, though, they're like kittens. Open the door in a room full of kittens. They'll all look up in unison. The Mikadono sisters are the same. Give them a common stimulus (usually Yu doing something normal that they can't comprehend) and you'll get triple comedy reactions that for me were three times as funny as one.
The show's not fluff, mind you. The Mikadonos' father is a nasty piece of work, while Yu's mother issues are real (although he's over the worst of them). Nonetheless, this is a charming, light-hearted comedy. Kazuki's for me the funniest sister, but it's close. (I loved her attempting a date as a female in episode 6, e.g. her attempt to be scared and girly at the House of Horrors.) As for Yu, he's wonderful. He really does become mum. He hasn't a manly bone in his body and doesn't understand situations that a normal person might recognise as sexy or romantic. He's as good a comedic engine as any of the girls. Definitely recommended.
