I'm just not too sure of the best way to interpret that ichiou... I'm assuming the point of the first comic (I'm a boy) is that, at the end, Ash begins to question whether he was wrong about calling Marona a girl due to him misunderstanding her question about why he phrased his first comment the way he did.
Basically, she questions why he used something like "souieba...dattare" and he thinks she's more or less questioning his use of "onnanoko" and then proceeds to spiral into doubt that leads to the second comic.
Yes? No? Maybe so?
Wah!What, Ash?I'm a boyCertainly a girlAsh, you're blushing!You're a girl, right?Aaah, I want to take a bath!Umm... Marona...Umm... Marona...What do you mean with "oh yeah that's right"?!Ash, you jerk!!Oh yeah, that's right, Marona is a girl after all.Suzushiro SeriSince you appear to be a girl, well...