Yo, I found two prewar Japanese pop songs about Madame Butterfly. Word on the streets is that these were part of the "Madame Butterfly boom" of 1933, itself inspired by a US movie version of the opera (I suppose it must have been this one from 1932, starring Cary Grant).

First, Miss Columbia's "O-chō fujin no uta" ("Song of Madame Butterfly"), with lyrics by Saijō Yaso 西条八十 and music by Koga Masao 古賀政男. (This combination was a big deal! Trust me.) This song is not that big a deal. Sample lyrics: "Nagasaki is for lovers, but the rain in the harbor is the rain of Madame Butterfly's tears" (恋の長崎、港の雨は／お蝶夫人の涙雨). The music, too, is standard-for-the-time "sad tango march," although I do like the little trumpet break halfway through each verse.

Next: Awaya "Queen of Blues" Noriko 淡谷のり子's "Madamu Batafurai no uta" which also has lyrics by Saijo. The music, however, was written by Sassa Kōka 佐々紅華, and is much more interesting than Miss Columbia's version. The lead piano sounds like a shamisen part, and there is just more going on overall. Sample lyrics: "The blossom falls, tears of petal wept/ The blossom in the outlander's mansion falls" (花が散るぞな、ほろほろと／異人屋敷の花が散る). (In the original, the connection between tumbling petals and flowing years is much more naturally made — the mimetic word for the two is the same, horohoro (to).)