There is a tl;dr at the end for those wanting a short review.
Warning: this show contains a lot of nudity, so if you are not into that or easily offended, this is your chance to turn away. That said, let's start the review:

There are not many serious harem/ecchi shows and that's mainly because the combination doesn't work well. Shows like Freezing, Change 123 and Ikkitousen have a similar setting and they often implement paper mache-like clothes purely for fanservice or rely on certain characters to keep the fans at bay. Tsugumomo does not do that. It has serious moments, followed by occasional humour because not the fans desire it, but the author himself. (Yeah, let this one sink in). He stated that whenever a new character is introduced, he wants to draw them without clothes as soon as possible. Let me quote him from ch 71.5: "The main part has no fanservice scenes! This is a grave matter. So I worked hard on the omake. Because it's hard on the author when there are no fanservice scenes, working on the chapters included in this volume ought to have been quite difficult. But now that it's done, I don't remember very well."

Why is it that I enjoyed reading Tsugumomo? The main character gets involved in a lot of harem and ecchi scenes and is quite a whimp, same as any other ecchi manga. However, he is determined to fight for a just cause and wants to keep improving himself to protect others. This too sounds familiar? The difference is that the fighting scenes are quite dynamic and the techniques interesting. But before I start explaining that into detail, let me explain the setting.

Kazuya Kagami always keeps his obi (a silk cloth) from his mother with him. It is only after falling off a school roof that the obi reveals herself as a person and saves Kazuya from falling by weaving the obi in a cushion. They start to fight against a so called Amasogi, an object matured quickly because of the owners' desire. They are unstable and need to be suppressed by the owner, or he (the owner) receives a backlash, equivalent to the item. This is done by exorcists, like Kazuya and their Tsukumogami. A Tsukumogami is an object matured over time with the owners desire and therefore stable. The first Amasogi was a wig and therefore, that owner goes bald after the battle. Similar cases for other items. The fights are pretty cool. The MC starts off weak, but improves greatly over time. His Tsukumogami, the obi Kiriha, can be woven into different shapes. The variety is great to see. The most common finisher attack is some spiral drill attack, immensely similar to Tengen Toppa Gurren Lagann's drills, but he also uses the cloth to bind around his legs to enhance their strength, or as a shield to block incoming attacks.

There are other exorcists who enter the story at a later point. All of them have interesting Tsukumogami, whose powers are based on items ranging from a daruma doll to a sickle with a chain and any item in between. Throw in fitting characters who -apart from the main characters- don't fit the usual tsundere, loli, big boobed etc type, yet are intriguing on their own. The side characters have one clear trait, yet don't feel all that one-dimensional, given the fact that most of them are minor characters.
Every character is portrayed naked at some point and as the manga progresses, the nudity occurs more frequently and the content increases to the point of showing everything of the female body. I've seen the first few episodes of the anime and they don't show nipples, but miraculously cover them. I'm seriously wondering how they want to keep doing that, because -let me tell you- it's impossible later on.

As mentioned before, the fighting scenes are dynamic. The artwork is amazing. Not Somali to mori no kami sama level, but exceptional nonetheless. I honestly don't remember the artwork at the start, but the later half implements amazing scenery, detailed effects, interesting and clearly shown items as well as the anatomy of the female body. If not for the fighting scenes, it would be mostly the artwork combined with the nudity that commend me to keep reading this.

TL;DR:
Story- 7. It doesn't keep you on edge and is relatively simple, but that is not the main focus of the story.
Art- 9. Amazing, the background, fighting scenes, objects and the anatomy are terrific.
Character- 7. The MC develops over the story, he becomes more confident and even side characters are quite interesting.
Enjoyment- 9. The interesting fights with a myriad of (often) japanese objects are fantastic to behold, but I would be lying if I said I didn't do it for the nudity as well.
Overall- 8/10. Starts off as a pretty mediocre show, but develops into something serious and interesting. There were some really dark scenes at a certain point. Something I didn't expect at first, judging from the genres. I would recommend this mostly to the male gender as it contains some shounen elements and nudity, but if female readers don't mind that, I would recommend this to everyone who enjoys some no nonsense action and occasional humour.