Funny you should say that. I went and dragged it over to one of the translators at DCTP and she said the name might be Kurosawa, and the name we can see entirely was probably Vodka's pun. I think I was in the wrong and the interview might be correct.
http://forums.dctp.ws/viewtopic.php?f=4&t=2169&start=15#p777781
ranscript from the cbox, cut to the most relevant points with minor fixes.
Chekhov MacGuffin: (27 Jun 13, 13:51) The mermaid guestbook came up again. What did I screw up, Fuji? http://www.detectiveconanworld.com/foru ... /?p=295425
Chekhov MacGuffin: (27 Jun 13, 13:53) It came up in regards to Q3 from this site: http://anokata.xxxxxxxx.jp/faq.html
Chekhov MacGuffin: (27 Jun 13, 13:55) If I didn't mess anything up, I'm going to have to go back on my previous words that Vodka wasn't in the guestbook. Of course, a pun like that is probably not his real name, even though Sherry used her real name.
Fujiwara: (27 Jun 13, 14:10) Awesome find that. My remarks: 魚塚 is definitely a play on Vodka just as you described. That's because it's not, in fact, a Japanese surname. I.e. no one uses it.
Fujiwara: (27 Jun 13, 14:12)
It could be read differently from Uotsuka, of course, but given how it's not an actual name and it's position in the guest book, either Vodka wrote it or it was a joke by Gosho, it was definitely intentional.
Chekhov MacGuffin: (27 Jun 13, 14:12 - 27 Jun 13, 14:14) I noticed Wikipedia turned up zero people with the name. I'm guessing it was probably Vodka judging by the context. Shiho probably would get an escort. The elephant in the room is if the Gin part is true though. As in the name on the far right. Per the interview given in Q3 here: http://anokata.xxxxxxxx.jp/faq.html
I doubt Vodka would use his real name, even if Shiho did.
Fujiwara: (27 Jun 13, 14:15) No, since Vodka is a codename it would make no sense for it to be his real name. Esp. given how it's not, actually, a name that people use.
Chekhov MacGuffin: (27 Jun 13, 14:16) By the way this might be useful: http://www.detectiveconanworld.com/wiki ... _manga.PNG
Fujiwara: (27 Jun 13, 14:18) Yes, well, all I can say is that the part of the next name that you see matches the Kanji for Kurosawa Jin (黒澤陣).
Fujiwara: (27 Jun 13, 14:30) But, yeah, the Gin thing woud really depend on the veracity of that interview, since you can only see the tiny part of the name and the original rumor might have been based on that bit ...
Chekhov MacGuffin: (27 Jun 13, 14:35) If you have any more remarks, now would be a good time
Fujiwara: (27 Jun 13, 14:38) Well, there's alternate readings for the given name, I suppose, but Saburou seems the most prevalent and none of them give off any BO vibe. Here they are though: Mitsuo, Sanrou, Kazuo