My own comic is still in the early stages and most of the cast has not been introduced yet, so I'm very curious to see how people respond to them. I have some guesses as to who will 'blow up', but we'll see haha
So far, according to the one tiny poll I took, Nora is my most popular character. Not at all surprising to me.
She's in the spotlight for the majority of the introduction. Being young, inexperienced, and in need of guidance and protection, I felt hers was a good POV to start with that readers could more easily insert themselves into and relate to, as they're new to the world as well. She's easy to figure out and understand as a character, and she's simple and straightforward for the most part:
An underdog with a fiery, passionate personality who makes her motivations and fears known right off the bat (She wants to follow in her older siblings' footsteps, be useful to them, and make them proud of her. She's afraid that she'll be a burden to them and never get stronger). Fear of failure and a desire for acceptance are both pretty universally relatable.
I'm not surprised that D is a favorite in Stick Figure Isekai either. Since he's not an Isekaier with a quirky, eccentric personality like Naota's- but just a normal kid with normal desires, he's more relatable. I also think there's just something nigh-universally appealing about flawed, underdog/average characters, especially in the early stages of a story. Give them a dream and some drive, and they can become very likeable.