YES! Early 20th-C. Ainu activist IBOSHI Hokuto has appeared at Aozora!

『北斗帖』 (Hokuto chō, "Hokuto['s] notebook") is a tanka collection in Hokuto's idiosyncratic two-line format. There are some rousing Ainu Pride numbers:

滅び行くアイヌの為に起つアイヌ
違星北斗の瞳輝く

For the sake of the perishing Ainu, Ainu rise
Iboshi Hokuto's eyes sparkle

... a long sequence about hemorrhoid* medicine:

ガッチャキの薬をつける術なりと
北斗の指は右に左に

売る俺も買う人も亦ガッチャキの
薬の色の赤き顔かな

"This is how to apply the ointment!"
Hokuto's hands: to the right, to the left (I don't even want to understand this one)

Both I, the seller, and the buyer too:
Faces as red as the ointment itself

... and, returning to the directly-about-Ainu theme, some wry observationals:

俺の前でアイヌの悪口言いかねて
どぎまぎしてる態の可笑しさ

うっかりとアイヌ嘲り俺の前
きまり悪気に言い直しする

Afraid, with me there, to bad-mouth the Ainu
How funny, their flustered state

Scorn for Ainu blurted out before me
Shamefully, they correct themselves

(Sorry for the rushed and shoddy translations -- still in tour guide mode -- strongly recommend a visit to the original!)