It's a very silly show... at first. Apparently, the manga goes on a journey from "daft fanservice" to "more serious drama", which didn't please its readers. The anime also has a bit of that, but it doesn't travel as far from its boob-obsessed starting point.
It's a samurai historical, set in a version of ancient Japan where breast size decides everything. Big boobs are worshipped. Flat-chested women are barely seen as human. Some clans have magic that lets you steal someone else's cup size and increase your own, which of course is the greatest power in Japan. Obviously, the absurdity is through the roof. The whole thing's ludicrous, from that goofball tit-obsessed lord to the copious nudity.
That said, though, there's serious content here too, if you dig for it.
Firstly, some of what happens here is sexual assault. Even if it's woman-on-woman, it might still involve swords, screaming and sadism. (Magically cutting off someone's boobs is bloodless and doesn't leave a scar, but it's still disturbing.) Then, on the rare occasions when a man is involved, things can get downright sinister.
Secondly, there's a lot of truth in what's being portrayed here, underneath the comedy boobs. Women did indeed have a shitty time of it in those days. Also, there are plenty of historical cultures in which arbitrary physical attributes (e.g. plumpness, or small feet due to binding) were used to measure a woman's worth.
I also like this gender-flipped portrayal of samurai-era Japan. There are still a few powerful men, yes, but most of the people we meet are female, even if they're filling roles that in real history would never have been permitted for women. An authentic jidai-geki will be predominantly male, male, male and male. This, no.
Our heroine is Chifusa, a samurai who believes that breast size is unimportant and that everyone should be treated equally. I like the sentiment. Her lifelong companion, Kaede, is a ninja whose breasts were stolen by the Manyuu family and is now obsessed with big boobs. Mostly Chifusa's. On seeing Kaede's antics, passers-by generally assume that they're a pair of raving lesbians. The show's first half is pretty goofy, but the second half introduces tougher, more troubled characters and gives Chifusa serious opposition. There's also a comedy surprise in ep.10 with a lover of small breasts. (Kaede isn't pleased by his praise.)
This show is daft as hell (e.g. the microphone in ep.10)... but, underneath that, it's following the form of samurai drama and is capable of getting surprisingly serious. Also, the "buxom is better" rule isn't being held up as a good thing. Chifusa disapproves of it and the show ultimately manages to say some quite nice things. I'd also recommend this show if you want practice listening to Japanese accents, e.g. the difference between "chichi" (upward tone) meaning "tits" and "chichi" (downward tone) meaning "father". "Chichi" is this show's favourite word and there are scenes where both "chichi"s appear in dialogue.
Will I ever rewatch this show? Very unlikely. But it's a laugh, if somewhat inconsistent.