The bunk bed was shaking violently, and the older sister, unable to resist her younger sister's moans, became aroused. (NHDTA-223)

A wildly popular bunk bed series. The younger sister, excited from having sex with a man, tries desperately to keep her voice down so her older sister won't notice, but soft moans still escape, and the bed shakes wildly. The older sister, noticing this, pretends to be asleep while eavesdropping on her sister's breathing, unknowingly becoming soaked between her legs. The man, having finished with the younger sister, sees the older sister's wetness and, without hesitation, joins in this delicious "sister donburi" (a type of sweet meal between sisters)!