This work is pretty bad in a lot of senses.
First as a yuri work, it felt out of place for the author to introduce the original yusha as the (potential) love interest of the Princess. I didn't go past chapter 4 so I wouldn't know much more about it. I don't like it a lot when they introduce hetero romance when it's a yuri work.
Second, the Princess's personality just doesn't cut it for me. Why is she so tolerant and weak minded? Why does she allow people to talk shit to her face? This is a personal remark, so some people may like this but I don't.
Third, the story's plot is a bit all over the place for the first few chapters. While I understand that the story probably gains a storyline down the line, I will not be continuing for the next reason.
Fourth, the side characters are awful. The yusha girl is likable and I don't have much complaints about her, but the other two are just plain ass bad. The Korone bitch just keeps being rude and unsufferable, but apparently nobody gives a shit and they just all tolerate it. The gunner man's personality didn't really shine through, but how did he wake up after being starved to collapse? I would have preferred seeing one of the frogs as their companions rather than any of these two. And the one good character (the doll) they were about to introduce gets eaten by the fucking dragon, like come on brother for god's sake. Are you trying to shoo away your readers on purpose or what?