chapatsu

[Pabappa]

Japanese 茶髪 /chapatsu/

Are there any other words where a morpheme appears with /p/ rather than expected /b/ or /h/, despite not following a closed syllable?

(Besides recent loans and onomatopoeia)

[Vijay]

ぱったり

[Estav]

ぱったり

Is that an ideophone? I thought the use of /p/ in those was considered a somewhat "regular" exception to the usual rules for the distribution of /p/ in Japanese vocabulary.

I don't speak or study Japanese, so I probably shouldn't speculate like this, but I'm tempted to guess that the use of /p/ in 茶髪 could be related via analogy to the regular use of /p/ in 金髪 kinpatsu "blond" and 銀髪 ginpatsu "silver hair". Those are two other hair colors listed in the Wiktionary page for 髪.

[Vijay]

You know better than I do.