[throwawayk7h]

there are more irregular verbs than just kuru and suru. iku and aru are also irregular, for example.

Irregulars notwithstanding, the conjugation pattern is actually completely lossless if you just remember the imperative form (e.g. 着ろ kiro, 切れ kire) instead of the infinitive, which is lossy (e.g. 着る kiru, 切る kiru). Then there's no need to have to remember, "oh... is this -iru verb group 1 or group 2?"

[klodolph]

They’re sometimes called “semi-irregular” because they are mostly regular with, like, one deviation. The list is not long and it is quick to memorize.

[plastic041]

Iku is kinda irregular but it's only itte and itta instead of ite/ita. Also aru/nai is more like antonyms rather than conjugation?