[kazinator]

Good catch: the -riru verbs, where the -ri isn't coming from the godan conjugation of ru, but is part of the stem before the -ru.

None of these are ever other than ichidan? If we imagine a -riru verb that is godan, it would have to go to -ririmasu.

That sounds like something only a ditzy weather girl called Ririko would say, for a gag. :)

FWIF, the "#words #v5r ?*りる" search does come up two hits:

The first one is 手を借りる, which is a classification error; it is a compound verb that conjugates exactly like 借りる by itself.

The second one is a curiosity: ラリる -- to get high on drugs. Supposedly godan, so it does give us ラリります, etc.

Wikipedia page on it with some etymology/origin notes: https://ja.wikipedia.org/wiki/ラリる

Well, apologies to Ririko there!