Ona Ken! 1.8 -Ushinawareta Akume

Fruits JAM's popular Ona-Ken! spinoff #4!
The lead voice performance by Nao Kasukabe earns the distinction of "Ona-Ken final boss"!

Prologue
The other members of Ona-Ken are caught in school events or wiped out by health,
leaving Nao alone to indulge her "onani life" in the empty clubroom.
But! In a bizarre twist Nao loses the ability to orgasm!
She asks her health teacher Setsuko "Secchan" Yamino for advice
but as Secchan listens to Nao's detailed masturbations day after day,
it starts to warp her sensibilities...

Female characters are fully voiced!
CVs: Rizu Sawashiro, Ruka Manome