One-track mind
As far as I can ascertain, there are no poems in the Kokin Wakashuu or Hyakunin Isshu that mention Buddha, and only one in the Manyoushuu. Specifically, 3841, by OHOMIWA no Okimori (大神奥守)
佛造 真朱不足者 水渟 池田乃阿曽我 鼻上乎穿礼
佛作る 真朱足らずは 水渟まる 池田の朝臣が 鼻の上を掘れ
hotoke tsukuru / masoho tarazu ha / midu tamaru / ikeda no aso ga / hana no uhe wo hore
"If there isn't enough cinnabar to make a [statue of a] Buddha, dig some extra redness from the nose of the gentleman of Ikeda [plus an extra pun on "Ikeda"]."
DIS! And apparently in direct response to poem number 3840, which was by the gentleman of Ikeda:
寺々之 女餓鬼申久 大神乃 男餓鬼被給而 其子将播
寺々の 女餓鬼申さく 大神の 男餓鬼賜りて その子産まはむ
teratera no / megaki mawosaku / Ohomiwa no / wogaki tabarite / sono ko umahamu
"At temples all over the place, the girl hungry ghosts say they want to marry the boy hungry ghost, Ohomiwa, and have his babies."
I know -- it's as though Nas and 50 Cent had travelled back in time and continued their beef there.
Anyway, Buddhism was clearly not a popular topic for Japanese tanka poets -- Shinto themes were much more common -- but I just recently learned that there was a whole separate genre, called wasan (和讃, "Japanese hymns"), which weren't tanka but were Buddhist and Japanese, right down to the 7/5 "line" structure.
Shinran wrote several books' worth of well-regarded wasan. Here's an example from 『浄土和讃』, "Pure Land Japanese Hymns", with modernised pronunciation:
誓願不思議をうたがひて
御名を称する往生は
宮殿のうちに五百歳
むなしくすぐとぞときたまふ
seigan fushigi wo / utagaite
mina wo shou suru / oushou wa
kuden no uchi ni / gohyakusai
munashiku sugu tozo / tokitamau
"Those who doubt the Mystery of the Holy Vow [of Amitabha]
as they speak his holy name -- after death, they will be reborn
in a palace [on the outskirts of the Pure Land], where they pass
five hundred meaningless years, it is explained."
Must... not... trivialise hymns... by... relating to own situation...
Shinranworks.com has a whole lot more of Shinran's hymns online, if you want more, although they don't include the original Japanese.
IbaDaiRon:
Being lazy, I read the English translation before the Japanese original, so "girl(boy) hungry ghosts" threw me (despite the lack of hyphens to fix the meaning as I took it).
Maybe change "girl" to "female" and drop "boy" altogether?
Anyway, any thoughts as to why Buddhism was a less popular topic?
(Slightly off topic, how do you know it's Obon in Iwaki? The Jangara groups make the rounds of the neighborhood, chanting and dancing. Started one house over at 10:30 this morning. Aiya.)