I don’t exactly know how to explain it, but I think “Eh?” is a bit better, since it more implies “loss of words” than “Huh?” does, which is a bit too direct or confrontational.
Is this the first time two strips have taken place on the same day? This one feels like an immediate followup to the previous one, rather than Ohta letting her hang for a full day (although that move is definitely within his wheelhouse).
"Eh?" is perfectly fine, but if you want to make it clearer maybe "You do?" would show her surprise that he's directly asking for the bag.
@rebel16 When Ohta found the fake confession letter from Odashima, strips 53 & 54 were same day, too. 56 & 57 were probably the same day, as well. (Ohta kabedon'ing Odashima, then Kashiwada being depressed at dinner that night.) It happens occasionally, even though the countdown still goes down when they're same-day strips.
@manabi even though it breaks logic often (hell, they shouldn't be at school 7 days a week) they all are supposed to be daily. even those two pairs you mentioned. the day counter confirms that, too