Ok, so this is from Little Busters, a manga from the interactive novel of the same name, not that you've heard of it...
but anyway, the girl (Tokido) just sent a letter to the guy (Riki) telling him to meet her in the garden, but to Riki's surprise the message disappeared right after he read it. Tokido has made a big deal of telling Riki she's a secret agent trying to defeat the "dark administration" of their school. He asks about the letter in panel 1, and she responds in the second speech bubble:
りき: これなんだけど 文字が消えちゃったのはどうして。。。？
Riki: It's about this. Why did the words disappear?
According to the NYW point results, it seems possible to transmit as many as 15 words...
Riki: This seems really shady...
Anyway, I have no idea if that's right... especially what NYW point is referring to. any help would be greatly appreciated. It seems like it's referring to the chemical reaction, strangely, but... from the context I guess that makes sense because in the next panel she admits to lying and just using disappearing ink. Still, I still have no idea how to translate this. Page for reference: