Sjo
Dubious Dutch transliteration used by Henk Arends, who describes it, in my opninion rather disdainfully, as a mouth-blown "orgeltje" [small organ] that can produce chords.
Arends, H.: Muziek uit Japan kent vele vormen. In: Akt 18;5 (Groningen, 1970) (p.153*, 157).