Indeed, especially for a language with forms of verb as regular as in Japanese. The whole language has two and a half irregular verbs. Compare that to Spanish and realize how fortunate you are to study Japanese verbs.
Spanish is not that bad: the conjugations are not gendered, while there are fewer than 20 major irregular patterns and about a dozen especially quirky verbs that you have to memorize in a few tenses (there are no 100% irregular verbs, most have at least some regular forms).
Source: I develop a conjugation app for a living