Name: Mihoshi Kuramitsu
Occupation: Galaxy Police Detective, First Class
ORIGINS
Mihoshi's origins are only really explored in the OVA series in any depth, where we know from the outset that she is the grandaughter of high ranking Galaxy Police officials. Later on, through the OVA3 and the Galaxy Police series it becomes apparent that Mihoshi's family (the Kuramitsu) are high born Seniwans who have a lot of influence within the Galaxy Police. This in effect seems to be the main reason she is able to stay where she is in the force, even though her performances have dropped since an 'incident' that has not wholly been revealed in the cartoon series.
Mihoshi in the OVA has a brother, Misao, who is also involved in the Galaxy Police. He is not introduced until OVA3, and although he is younger than she is, he is fiercely protective of his sister's vulnerable nature - even willing to kill to protect her. This indicates that Mihoshi's family were quite closeknit when she was a girl - although they have drifted apart later on since Mihoshi does not recognise the grown up Misao at first sight. (This is all OVA 3 information, but as far as I can see it does not contradict anything we're told in OVA 1 and 2). According to the OVA3 and the Galaxy Police series, her mother Mitoto works as a cleaning lady at Headquarters and it seems to be from her that Mihoshi inherited her carefree spirit and her ability to get into places without really trying. Mitoto often appears in strange places around Headquarters, whilst Mihoshi manages to get into Washu's laboratory with little effort at all.
Mihoshi is also a distant descendant of Washu, although this is only included in outside of the show material (namely the SHIN novels by Kajishima). She is directly descended from Washu's former husband Mikamo and their son Mikumo, but it is unknown as to whether this connection will ever manifest in the television series.
In the Tenchi Universe series, Mihoshi is simply a detective at the Galaxy Police. It is not made clear how she became a detective or whether her family are still involved in proceedings. All we know is that at some point between Kiyone's graduation from the Academy and the start of the TV series, she was assigned Mihoshi as a partner. This suggests Mihoshi probably did go through the Academy like Kiyone - but it doesn't indicate how she managed to pass the exams. Why the Galaxy Police are so tolerant of her is something of a mystery - but there is never any explanation or indication that she has powerful friends lurking behind the scenes.
Tenchi in Tokyo gives much the same vague picture - Mihoshi and Kiyone are partners whose only background information is that they were pursuing Ryoko and Washu for the theft of the Juraian gemstone when they crashed to the Earth. No mention is made here either of the Kuramitsu family or any other connections Mihoshi might have.