I am fairly sure this is an English language web comic. So English is the original language. Hence the British flag on the icon. Although it is set in Japan.
Dense protagonists are annoying when they are dense while also whining about finding love. if a character is dense when their focus focus is on another task, such as surviving, it makes a lot more sense.
I personally ship him with Suzune-sempai as she is a lovable dork who doesn't play silly tzundere games. I also like the idea of co-summoned couples in isekai as there are no issues with age or power dynamics.
Idea: page 7 "But Tozaki-san enjoyed the sparklers" -> "But Tozaki-san enjoyed handling the sparklers" it is slightly awkward phrasing but still believable while preserving the misunderstanding
It depends on the school. I personally have only seen police at the school where I taught when the DARE officer comes to give talks about drugs and the one time they did a drug search after two sophomores were obviously high during ELA class.