#1 Its borderline hentai
That Mouse was produced with the simple and singular goal of pushing the boundaries of what ecchi can get away with is rather obvious, and whether or not that is bad depends on if you are looking for that kind of thrill or not. The characters fulfill obvious fetishes, from the large-breasted beauty to the eccentric tomboy, all adorned with bright hair colors and voice actors presumably selected for the quality of their moaning alone. There is also full nudity on display, so make of that what you will.
What bothers me is that the need for all this ecchi content blocks the show from doing anything else that is noteworthy. The characters are barren as far as writing goes; a collection of simplistic female characters abiding by well-known tropes, all unified by their loving devotion to the main character, including his presumably underage students.
Every character is eager to ditch their clothes or put on fetish gear given the chance, and the camera certainly knows where to aim itself during all this, but in any other scene both the animation and directing work are amateur at best. A highlight came for me when a bunch of characters were hidden behind a shipping container, which was so poorly drawn it looked more like a random metal box that kept changing dimensions between shots.
You don’t watch a porn for the story and I presume the same applies to hentai, but Mouse tries to sell itself as a comedy harem mixed with a detective show set in a high-tech future, only to then entirely neglect that second component. Action scenes are devoid of any excitement, the characters are (as I mentioned) utterly boring, and the stories aren’t complicated enough to make a detective show work or play to the strengths of its futuristic setting.
#2 The childish storytelling
What confuses me is the disconnect between the kind of story that is being told and how heavily the show pushes its pornographic content. Mouse is about a master thief who performs improbable thefts to uphold his family’s legacy, joining the ranks of Sly Cooper and Carmen Sandiego. One storyline sees the cast preparing to steal an entire building just to frustrate the police officer obsessed with the Mouse case, another has the cast dive into a digital world to save a trapped friend. It’s all lighthearted and adventurous, the kind of storylines I could see working for a show aimed towards a younger audience. Except, that is not going to happen with the amount of boobs on display, now is it?
The writer would have been better off keeping either the fun misadventures of a bunch of colorful thieves or take the plot in a more serious direction better fitting for the mature-only themes of the story. Having a multi-part storyline where all the characters play dress-up to perform comedy sketches is a good example of this. If you came here for the erotic content, then you are going to have to sit through some tortuously poor comedy bits and a story that just makes you go “I am too old for this crap.”
I don’t exactly have the best frame of reference when it comes to ecchi, but Gunsmith Cats comes to mind as a nice comparison. That show was fun, exactly because its sexy elements neatly matched the explosive adventures of its main characters. In fairness, though, Gunsmith Cats is more of an action show and far superior to… this.
#3 The performances
Browsing through the cast of Mouse I was surprised to find a number of familiar names on there because the performances gave the impression this production was far more amateur. I mean you got the voice of L from Death Note representing our titular thief, except he does so while sounding like he was only half-certain of what character he’s supposed to be voicing. Despite having handled much more difficult roles before and since, here Kappei Yamaguchi is just unable to keep a consistent tone and quality to his acting.
All the characters suffer a similar fate, but especially side-characters like the police officer are either far too over-the-top or entirely flat. The worst of the lot is the highschool student Machiko, who appears frequently and is voiced by Tomo Saeki. I am sure she tries her best, but she just ends up sounding like a thirty-something woman trying to impersonate a teenager.
I didn’t gamble on trying my luck with the English dub, but a daring friend who did informed me it sounded akin to a primary school play.