The title, "Na-Geanna" (in Gaelic, "Wild Geese"), refers to several things. First, it is the name of an Irish Single Malt whiskey, produced by Hennessy. Because of EU trade restrictions, it is only available for sale in Japan, and has to be imported specifically into Europe. At the same time, "wild geese" was a term used for Irish mercenary soldiers, employed by various governments, groups, and movements as far back as the 13th century. However, the term was first specifically used in 1607, in reference to groups of soldiers under Hugh O'Neill (Earl of Tyrone) and Rory O'Donnell (Earl of Tyrconnell). According to another source, the key relevant date is 12 July, 1691, the defeat of the Irish Jacobite Army at Aughrim; afterwards, some 6500 went into exile in France, and later served in the armies of a number of other European sovereigns. Finally, The Wild Geese is the title of a 1978 Richard Burton/Roger Moore movie, and Cold War-era slang for mercenaries, in particular former British or American military men, now throwing their lot in with the highest bidder.

But how does all of this relate back to Mahoromatic?

In the show itself, the only clues are offered by the preview narration for episode 26:

"Long ago, a man left his homeland behind. The man drifted to a foreign land and was enamored by the spirits made there. He built his own distillery and lived the rest of his days there. The distillery hailed the man's accomplishments and made a spirit from the man's homeland. But, it was far too gorgeous...and was unlike any of the spirits from the man's homeland. Its flavor was both sweet and awfully melancholic..."

The "man" in question is Richard Hennessy (1720-1800), himself a Wild Goose soldier in Dillon's Regiment, in French service. He saw combat at Dottingen and Fontenoy and in 1765, began producing the Hennessy brand cognac brandy.

Of course when his biography is mapped onto the events of the series, it becomes obvious that the description largely applies to Suguru Misato as well. Hired sword and vagabond, he has almost nothing to live for in the present, just the memories of the past. Whether or not he is aware of any such kinship with Hennessy, what is clear is that nearly the only way he is ever able to find solace and comfort is by resorting to drink. The "flavor both sweet and awfully melancholic", then, are the memories of the innocent and happy times that rush at Suguru: times whe he had known death twice, but was for once convinced he would not have to deal with it any more. Times when he had friends and people he cared for, and people who cared for him. Ultimately, just as for any mercenary, there is no real return to the past. The only thing there is, in due time, is death.