Thank you, everyone. This gives me something to think about.
A quick note: Mr. is fine. As much as I appreciate it, I have no doctorate and do not wish to have anyone think I am claiming such.
Dr. Vovin, I really appreciate your response. I was afraid that such might be the case, but when I saw the people replying here I thought that maybe I was missing something. Of course, now I'm also looking at picking up more books or finding an institution where I can go through them. I'll keep my eyes peeled as I'm going through the texts to see if I notice anything.
Dr. Jamentz, thank you for that lead on Hyakusai-ji. It led me down a rabbithole of the history that they have online. I am quite curious what they would say: they seem to claim founding back to Shotoku Taishi, the Koguryo priest Eiji/Hyeja (恵慈), and the Paekche priest Kanroku/Gwalleuk (観勒). And of course: Thank you, Japan, for having both a 百済寺 ((ひゃくさいじ) in Shiga and a 百済時 (くだらじ) in Nara, because that isn't at all confusing. ;)
And of course, if anyone has other suggestions, I'm all ears.
Regards,
Joshua Badgley