Umisho is a very simple fanservice anime with a very basic premise added together with a school swimming club premise. After a few swimming club hijinks. A strange girl shows up in a strange way and joins a swimming club. The male lead is a buy who manages the swimming club despite not being able to swim. The male lead has background ties with two of the potential love interests though it's obvious which way it is heading from the start. The male lead is also the only character that the girls in said swimming club could possibly like. Despite this factor there is at best a confirmed love triangle and it's not even clear if it's really love at play there. Hijinks ensue including lot's of fanservice including breast grabbing, breast envy, random stripping, implied girls love situations and clothing malfunctions.
The style of the anime is pretty soft with watercolours being mostly used. Characters are expressive but minimalistically drawn a lot of the time. Still it doesn't go out of it's way to engineer a style too far away of the norm. Movement is generally captured reasonably well but avoided in a lot of scenes if possible. It has some recycled animation but the flaws are not too glaring. The fanservice in this involves a lot of breast groping and that of course is animated just like you'd expect from a fanservice anime with any budget. The swimming is largely not animated too greatly but gets the point accros. It has to be said that if you're a swimming enthusiast you might want to skip this as it is not very realistic at all especially Amuro's swimming style as the strange girl that joins in the first episode is dubious.
The characters enjoy consistently solid voicing even the annoying comedy relieve characters don't sound bad. The voices used for all characters are pretty comfortable though still follow the high pitched girl voices in quite a few places. Personally only Makio gets near to being annoyingly high pitched but it's still not as bad as quite a few anime. Shizuoka's voice also is not very strong and a little distracting. The back ground music isn't striking which is quite okay but it doesn't lift this series up either. The opening is generic and honestly not very good while the ending theme is pretty much consistently unimpressive itself.
The characters in this anime are quite simple Amuro is a cloud cuckoo lander, a daydreamer type of girl whose ways of thinking are simply strange. The male lead is a generic straight guy who can't slim and comments on the absurd behaviour of others while having no personality of his own. Zuka or Momoko as she's also called is the first girl you get familiar with. She's basically the tough and rough leader type who is also a girl. Maayaa is another characters that joins halfway through the season she's the bossy unselfaware type and doesn't have much going for her. Shizuoka serves as a secretly perverted wallflower and is probably the most unique character in all of this she also gets a ton of fanservice because her breasts are of course the biggest. Overall the characters are fairly stock with little depth but for an anime of this lenght and type as well as having quite an expansive cast they are far from the worst. The ''comic relief'' Captain Ikariya however is defnitely is among the worst in comic relief characters.
This anime is a simple guilty pleasure for fanservice lovers there is no reason to watch it if you're not watching it for the fanservice. There is no real romance in this and the competitive swimming element of course has been done before and better. If you are expecting cute girls in random swimming club situations providing fanservice to you with some throw away attempts at humour and you like that idea then you can watch this anime to get what you desire. Simply put this anime exists as a vehicle for fanservice and perverted humour don't expect anything else from it or be burned.
If you're not into ecchi/fanservice aimed at the male demograph, consider this to be rated 2.5/10 by yours truly.