I'm definitely leaning towards Ai. Like a few people mentioned, Nadeshiko's reply best matches with what Ai sent her.. To me, the "You''ll have to show me tomorrow" implies she needs to see more of the item in the pic and since Ai only sent the
A few things that also make me think it's Ai:
- Chapter 26, Nadeshiko is on the phone with her gf and says "you like the movies huh." And in this recent special Ai picks out a book specifically for the movie shoot location article. This one's kind of reaching haha.
- Chapter 40 when Nadeshiko does the kabedon thing to Ai
- chapter 55 when Nadeshiko's doing everyone's hair theres just.. I don't even know how to explain this, unspoken communiction?
- She's also just a lot softer? when interacting with Ai. Often offering things like sunscreen, snacks, and offering to do her hair without being asked. This may just be in part because of Ai's personality though.
Anytime she's on the phone (ch 26) she seems to get lightly teased which makes me believe it can't be Megumi since it's usually the other way around. Miho seems to tease a bit too much. She's also just a lot softer when interacting with Ai.
Of course this could all be a bunch of red herrings and mean absolutely nothing
TeamAi