Like all good Lebanese tales, this one leaves a lot of unanswered questions. Why, for example, did it take 19 days for the authorities in Beirut to admit that their State Security men had arrested the Red Army members - an operation carried out on 15 February? How come the interior and foreign ministers - not to mention Adnan Adoum, the Prosecutor General - spent days denying any knowledge of the detained men?
Mr Okimoto was part of a pro-Palestinian Red Army hit team that slaughtered 20 pilgrims at Tel Aviv airport in 1972. Released by the Israelis in 1985 - along with hundreds of other prisoners in exchange for a handful of Israeli soldiers - he disappeared in Lebanon, leaving the Japanese authorities furious at being unable to secure his extradition. Even now they may not get their men as quickly as they wish. If charged with forgery, the five could spend at least three years in a Lebanese prison.
The Syrians, officially refusing to involve themselves in Lebanese internal affairs, must, of course, have been well aware of the arrests; and Damascus may expect Japan's thanks. Lebanon may also expect some gratitude from Tokyo - perhaps in the way of reconstruction investment.
As for Mr Okimoto - along with Masao Adatchi, Kazuo Tohira, Haruo Wako and Mariko Yamamoto (the only female detainee) - he must face a lengthy trial in Beirut.