T28-525 - On the day my parents were away, I fucked my sister all day until I was drained.

Mari-chan is erotic because you can tell she's really trying. Why doesn't she win any awards?

It's a work that just keeps going at it with the common sibling trope, but given Takasugi-san's baby face and increasingly curvy body, it might have been better to make the uniform the main focus. I understand that the setting is at her parents' house, making a uniform difficult to justify, but since it flows from her casual clothes, it lacks that 'little sister' vibe, which is a bit disappointing. If the setting had been more intensely erotic, like a nymphomaniac, I might have rated it higher even without the uniform.