Mihoshi plays an important role, in addition to comic relief and contributing to the plot of
the series, that is the role of contrast. Some sources describe Mihoshi as an "adult innocent". I
see it going deeper than that, she is a Pure Innocent. Even the other innocent characters, Sasami
and Tenchi, are aware of and understand all the sexual innuendoes going on while Mihoshi seems
blissfully ignorant of anything impure. It is her "Pure Innocence", as well as her more
western appearance, that
provides contrast to the lecherous and scheming character and even the awareness of the other
innocents. This contrast brings the other characters more clearly into focus and amplifies their
impure characteristics.
This technique has been used in other animes and mangas to great affect, most notably in
Dragonball. In Dragonball, however, it is used to exemplify the purity of the hero Goku by
contrasting him to a supporting cast of perverts, but the concept is the same. It is more evident in
Dragonball because the Pure Innocent is the central hero of the series while Mihoshi is just one
member of an large cast.
Mihoshi also contrasts individual characteristics of the others. She represents the law in contrast
to Ryoko the lawless pirate, her modesty contrasts Ayaka's arrogance, her carefree attitude
contrasts Sasami's sense of responsibility, and her impulsiveness contrast's Washu's analytical
ways.
They say that eyes are a window to the soul. In anime where symbolism is given preference to
realism, this is especially true. The typical rule for anime is the bigger the eyes the younger the
character. Mihoshi, who is 23, has as large eyes as anyone in the series. Washu, who appears in
the form of a young girl (about 10?) has very small eyes. The eyes reflect more of the spiritual
youth and
innocence than physical youth. Mihoshi's eyes reflect her inner purity while Washu's illusory
youth is betrayed by her eyes.
When Mihoshi confronted Kagato in episode 5 of the OVA, Kagato made reference to her past exploits and how she was not the officer she used to be. Her superiors at Galaxy Police also acknowledged her past accomplishments. Hopefully we will learn more about her past, and see a return to her former glory, in the upcoming continuation of the OVA.
Mihoshi may be lazy and accident prone, but she is not, as many maintain, incompetent or stupid. In Tenchi Muyo! Her superiors admit that she is a competent officer, their only complaint is the amount of collateral damage she causes in apprehending criminals. She also tends to get carried away, doing more than is asked of her (seeking to apprehend Kagato instead of merely reporting any sighting of him) and jumping to conclusions (assuming Tenchi's inviting her to return was royal Juraian permission for her to be stationed on Earth). These faults apparently stem from over-enthusiasm, not stupidity.
In the latter series' Mihoshi seems less competent than in the OVA. Kiyone may be to blame for this. In the first episode of Tenchi Universe Mihoshi pursued Ryoko and forced her down on Earth (although Ryoko was drunk at the time, but this dose not seem to be uncommon). Had Tenchi not happened along and revived Ryoko, Mihoshi may have succeeded in capturing her (although they still would have been marooned on Earth). She also seemed a fair pilot of her mecha aside from that one trip-up on the can, which she was able to recover from and resume pursuit. Again she may have been able to apprehend Ryoko if not for the interference of Katsuhito/Yosho, although since Ryoko was playing the damsel in distress for Tenchi we don't know how well the mecha would match up to her if she chose to fight. As to her forgetting that Ryoko was the space pirate in episode 3, that seems out of character for the OVA Mihoshi and may have just been included for comic value. There may, however, be a deeper meaning when she tells Ryoko to beat up the evil space pirate if she ever shows up. I think Mihoshi knew that Ryoko was the pirate but she also recognized that Tenchi was having a positive influence on her. Because of this, and on behalf of the friendship Ryoko had shown during their time on Earth, Mihoshi was telling her that she was letting her off the hook for the time being, as long as she continued to be nice. Yes, it is naive of her but it is in character to believe in the basic goodness, or potential goodness, of her friends.
Then Kiyone shows up. Mihoshi apparently got her memory back because she doesn't seem surprised when Kiyone names Ryoko as a space pirate. And when Kiyone summons another mecha that, except for the color, looks identical to the one Mihoshi had in episode 1; Mihoshi promptly crashes it. Unless there is a significant dissimilarity between the controls of the blue and the pink models of the mecha, the only difference was the presence of Kiyone. What is it about Kiyone that causes Mihoshi to loose her abilities to function normally? Well, the most obvious explanation is that Kiyone is a psychic vampire that feeds on Mihoshi's intellect, but I think it is simpler than that and will use examples from my personal experience to illustrate "The Kiyone Affect".
I am lazy but generally enthusiastic about my work, somewhat like Mihoshi. I have had to
work with one person in particular who is an overachieving kiss-up, much like Kiyone. When we
work together this person is only too eager to pick up the slack if I hesitate even a moment.
When this happens I tend to slack off more, knowing that my co-worker will carry our team,
though when I do, he tries to guilt me into working harder, but more subtly than Kiyone does
with Mihoshi. When I do try to match his pace my work gets sloppy and I make mistakes. It
seems to me the reason Mihoshi's abilities seem to degenerate when Kiyone is around is due to a
simple personality conflict between a carefree slacker and an uptight overachiever.