I'm not good translating, but from what I was able to understand, Iori comes asking Ako to have lunch together, and her sentence is cut short by the scene in front of her. Ako seems to have forgotten her bento, which has been delivered by her little sister. --- In the next picture, they're amazed by how much they look alike. Chinatsu comments on how squishy little sister's cheeks are, and Iori(?) compares their softness to Ako's boobs. Hina thinks Ako's sister is cute. --- In the last picture, Hina offers to wipe little sister's cheek, while Ako's mind begins to run wild thinking about Hina's handkerchief. Little sister thanks "Big sis Hina" and asks her to lean down a bit. Ako's somewhere on her way to cloud nine thinking about "Big sis Hina", and what follows is too much for her maiden heart.