there is some dispute about how gemination fits with japanese phonotactics. one analysis, particularly popular among japanese scholars, posits a special "mora phoneme" ( "mōra onso") , which corresponds to the sokuon . however, not all scholars agree that the use of this "moraic obstruent" is the best analysis. in those approaches that incorporate the moraic obstruent, it is said to completely assimilate to the following obstruent, resulting in a geminate (that is, double) consonant. the assimilated remains unreleased and thus the geminates are phonetically long consonants. does not occur before vowels or nasal consonants. this can be seen as an archiphoneme in that it has no underlying place or manner of articulation, and instead manifests as several phonetic realizations depending on context, for example: