Mesugaki Summer Life

Your younger sister, Yuzuha Tsukino, is an honors student who excels in both athletics and academics.
You, the mediocre big brother, kept your distance from her due to the disparity between the two of you.
After finishing the closing ceremony before summer break, you come home and accidentally look into Yuzu's room and see her in her underwear.
“Onii-chan gets excited when he sees his little sister in her underwear, doesn't he~♡”
However, the honor student little sister… was a lewd brat behind the scenes.
“Onii-chan’s summer vacation belongs to Yuzu.”
The mesugaki who found your weaknesses, and you who will find her weaknesses ─ the sweet and spicy summer vacation of just the two of you begins now.