【spa pants】A manga about spanking a little boy

<東方Projectの二次創作です>
This is a manga in which the older sister, Satori, spanks the younger sister, Koishi, as punishment.
It is designed for all ages and focuses solely on “spanking a child who misbehaves as punishment.

-40 pages of text
[Contents] 2 small stories, 14 one-page comics, etc.