I don't think it's very different; it's clear that Fumi's decision is motivated by her inferiority complex towards Sakura (which, frankly, doesn't make sense, but that's what the author wants). And although Shinobu tried not to expose Fumi, which she avoided by rejecting the producer's proposal, instead of understanding, she prefers to "prove" that she too can be like Sakura (a nonsensical thing that clashes with her personality so far). And well, I think the final chapter will have parallel "sex" scenes between Fumi and Sakura. While it's not real sex since they're acting, in the end it seems like they're cheating on Shinobu with others (although Sakura's is redundant, Fumi's is what leaves a bad taste in your mouth). Airi fried all the brain cells of Shinobu's character to make her just another cuckold in her works.
