I’m reading わたい、定時で帰ります。 (No Working Overtime!; a tv drama as well as a novel; might be of interest to folks considering working in IT in Japan).
I’ve just encountered the following sentence:
The character 結衣 (ゆい）is drinking beer at a restaurant, from a ジョッキ (beer mug). At first I thought it was an irregular conjugation of 扇ぐ or 仰ぐ, but I think it is 煽る, which usually means “to fan”. In that case, there’s no irregular conjugation. (Edit: Per @Leebo, this is 呷る.)
It’s always surprised me how few irregularities there are in Japanese. See https://nihongoperapera.com/dirty-japanese-guide-irregular-verbs.html.