Did you all forget he have a fucked up xp penalty for everything he have?
When they first met, the girls who barely stand againts kobold(?) have higher level than him who doing solo for days against a lot of monster. Also the fact that his level isn't even eligible when he tried to join the guild.
Perhaps his skills also had growth system? If all his acquired EXP was shared between all of his skills, that might explain why his level grew so slow.
Nothing much really. I've been reading the WN with google translate for.....awhile. It takes time with how many chapters this story has. But Falsity(The name GT gave it for me) is kinda a fake weapon skill. And he got it when he didn't have the ability to have learned one yet. It's him putting EVERYTHING he has together into the strongest quickest most destructive attack he can do at that time. And it pretty much ALWAYS wrecks his body when he uses it, to the point where currently he's trying to put together the best VIT gear he can in the story so that maybe any given real fight he has to participate in doesn't dust his bones, shred his muscles and explode his blood vessels multiple times a fight. Because his skills are outleveling his body due to the effects of Jack of All Trades and Unproductiveness. (And Jack of All Trades seems to be converting xp into empowering skills or allowing him to use them all. Unproductiveness we still have no idea what the good side in it is 300+ chapters forward but we do know that ALL OF THEM have some strong benefit to them....its just hard to tell what the hell they are when they are named so poorly.)
... And no one caught that this is the only person in the entire world that Haruka can remember the name of.
He can't even remember the name of the class president or the people who moved in with him for a week, he just gave them amusing names like "Bitch Leader," "Nudist Girl" and "Vice President B."
But he knew Tanaka's name instantly.
He had Tanaka pegged as a violent and dangerous sociopath long since before they isekai'd.
The only time we've seen Tanaka at all before this is Chapter 5, page 6, and it's mentioned so fast both in the manga and WN/LN that you won't catch on to the fact that Tanaka is the ONLY name the main character remembers or uses the entire story so far. (In the WN it's like, a paragraph, about how the math nerd is being picked on by the delinquents.)