Kind of hard to say, for volume 1 it's kind of a spoiler (out of around 17 volumes total for the series) that gets resolved by the end of the volume, but I don't really think its much of a spoiler. It does wave the question of Ririto's gender around for volume 1, but I think there was enough hints to make the viewer lean more toward Ririto being a girl. Kurume Tarou (male lead), remembers Ririto as being a girl from his childhood memories and Eve is an embodiment of his's first love feelings for Ririto (and is an idealized version of Ririto) appears starting chapter 1.
I was quite torn on adding the tag since I’ve never seen how a character like this is handled, but I wouldn’t say so. NWF_Renim got most of what I was thinking. I went back and checked and in chapter 7 we find out she’s a girl. Since that’s so soon I wouldn’t call it a spoiler.
Sounds like a "no" then. Usually, unless it's a big twist that impacts the whole series, something that only lasts 1 episode or volume to be revealed ranks as a "super soft - to not" a spoiler.
