Makes sense to add TL notes about certain details of korean culture, but don't add explanations as to what is going on. The dialogue is supposed to convey that.
@PankoPanko
Agreed. Though I must say the author can write some good combat scenarios, it's taking too long and there's been far too many interruptions. Hope everything settles down next chapter.
Him actually being a 30 years-old man has almost no impact in the narrative and we have no idea what the sensei's reasons are for accepting his confession, she just goes along with him.