2 swinging chapters but the story start smelling ntr from the light hair couple/sibling.
looks at the cover, the dark hair girl is become sadder, cover chapter 1 she had straight line lip (same as her hair clip), cover chapter 2 she had sad face (her hair clip is up turn - sad)
while light hair girl is become more mischievous, cover chapter 1 she had simple smile, while cover chapter 2 she had cat smile 3.
if this going this sure would be swing turn ntr-cheat story.