The manga started extremely well, with a fun concept and solid execution. I didn't even think having other characters join the main characters was a bad idea. The world building was cool, there was enough time spent both in the isekai and in Japan, and the introduced companion characters are distinct and interesting.
But then there's this shift when a new antagonist is introduced that... essentially uses magic to enslave a bunch of women and borrow/steal their levels. He has his sights on the main character's love interest (the female lead) as well as the other female who's joined them for a lot of their recent adventures. He tries to use the magic on her and fails.
And from that point forward, the story loses its quality and most of what it had going for it, because once more we have a series where the main character isn't allowed to even think of killing an evil person who is a danger to everyone around them. This gets the main character
stabbed
and the female lead
kidnapped for a short while.
And what is the reaction?
Prank the guy really badly.
I kid you not, they decide
scaring the guy
is fair punishment, and partly because his first victim still has feelings for him. It's like watching a Disney television special where kids use confetti to capture a hardened criminal. It's goofy, immature, requires several characters to be written out of character, and ruins the rest of the series.
Dear mangaka around the world: If your character isn't allowed to kill in a swords and sorcerery world, don't write antagonists who do things so evil they ought to be executed for it.
Beyond that, the romance becomes naive and frustrating so... probably not worth reading after the first 30 or so chapters.