Most Japonic languages have a relatively simple and transparent morphology. Their verb morphology is usually characterized by a highly agglutinative structure that exhibits little morphophonology, with only a few conjugation classes and a handful of irregular verbs. In sharp contrast with its relatives, Dunan (Yonaguni), a highly endangered Japonic language of the Southern Ryukyuan branch, spoken by approximately 400 speakers located on Yonaguni Island (Okinawa prefecture, Japan), exhibits a unusually complex verb morphology for a Japonic language, mostly due to some drastic historical changes. The verb morphology of Dunan seems be the most complex one within the whole Japonic family, and a systematic description challenges in several interesting ways morpheme-based approaches. The following presents an outline of the verb morphology of Dunan, limited to the basic synthetic forms of regular verbs. Focus is put on the partition of verbs into classes and its morphomic pattern. Three morphomic factors are identified as partitioning verbs into conjugation classes: stem alternation, suffix allomorphy, and metatony. The resulting system of paradigm classes is found to be opaque and to show little interpredictability between paradigm cells, i.e. few reliable inferences can be made from one inflected form about other forms. Morpheme-based approaches are not well-suited for the analysis of Dunan's verb morphology, which rather calls for an abstractive Word and Paradigm}approach.