This didn't have any romance whatsoever in it, why would anyone put it into that genre? o.O
Even the "romantic subplot" is an exaggeration: one girl blushing and imagining things in the beginning and then never reappearing, another that figures out she was misjudging the protagonist, the highest point being a date they were being tricked into by a third person about in the middle of the storyline and then never reappearing again like the other girl because the rest of the story is "overseas" so to speak.
Very disappointing.
As for the rest, I pretty much agree with most if not all of the critique below.

The beginning and middle were great. Good characters, terrific fights, and a little touch of romance. However, the last arc totally kills it. 300ish chapters and the ending does not tie up anything. Certain characters are not even mention. The ending does not have to be happy to be good. All it has to do is answer the questions and solve the plots it raised up. It does none of that.

This manga start of great then beginning to turn out more better but then the ending really disappointment to be honest. It was a unexpected disappointment. Their secret of being switch was never revealed to anyone nor did they got switched back. It was like this the author was in a rush to end this manga.It like a mystery remain unsolved even to the very end which I hated the most.I mean i love this manga but the author just had to end it with like a cliffhanger ending.If i were the author would at least add more chapters after they ended their fight with the company behind academy of hell then blah blah after few weeks have the 2 scientist found them told them how they ended being switched blah blah then switch them back, they both go back like nothing happen but then their friends and the girls see something different why they act strange but not strange it like going back to how they were before so they ended up asking so they revealed their switch then blah blah they accepted the truth but still hard to believe then blah blah at least let the nerd guy ask yuna out since they seem to like each other so i want to at least see them together at the end. P.S I FREAKING HATE WHEN AWESOME MANGA ENDED UP WITH A FUCK UP ENDING IT JUST RUIN IT which = those awesome manga with fuck up ending are not awesome it will = great only since the ending ruin it so i'll give this manga 8/10 when it can be 10/10 if it only still continue and were not having a ending like a rushed ending.

But the comic slowly degenerated into a broken mess. The artist does an okay job but the author ruined the story completely. It's actually worse than Andromeda after Robert Hewitt Wolfe left the production.
The big "story arc" mentioned by others is so bad it's utterly painful to read it.

It is fun to reach about the growth of the main character but at the same time you started to wonder what happen to everything else. For example, it started out with love/reason to fight then it turned into just pure fighting. Some character disappear without a reason even though they are the one that started off the series like that Karate girl. Some character just disappear completely after being there for like 2/3 of the series. It is like reading a manga that is center around the main character and only the main character while ignoring everything else. And then end it with a rush ending in which the original plot pretty much die.

Meh. It started really awesome and kept that up for about... 15-ish volumes. Then the huge arc that starts is kinda meh and the ending feels like a complete failure. It's like the author just completely changed his mind left all the plot elements hanging. I mean usually a rushed ending will at least wrap up SOMETHING.

I read all 31 volumes an thought something would come about his love live. No nothing happened, it just ends like that. There were fighting on the island than BOOM the ceo's come in an tell the truth behind the island. I mean what is up with that? There was no continuation on the fact they switched minds in the beginning. Just oh hi nice to see you. There was much potential in the series. It is a shame for those who have read it and will read it later on.

This is not like angel densetsu. A lot of the comments here mention it but this becomes much more just about fighting in the later chapters and nothing about what you'd think it would be. Reading the description I figured it would be something funny, about a nerdy guy in a thugs body and hilarious misunderstandings ensue, and it is, for about the first ten chapters, then the hero gets dragged into fighting and everything becomes about fighting and action. Also I question the return of the other character in the main character's body, every time he fights, it sort of annoys me because A. he is so much less than who he was that the fights he's in pale in comparison to the hero, and that he does nothing but complain about the weak body at first, and instead of making it stronger he learns an art he didn't know, discarding the numerous others he did? wheres the logic? why not just train the body? lastly, I don't want to spoil it but lets just say things get kind of stupid... lets just say, an evil organization is involved. To shallow for my tastes, the characters adapt into their changes far to quickly, and honestly they could have told the same story without the body swap and it would only cut out maybe 4 or 5 chapters.

5/10, I'm being generous because the potential was there, they just took it in a very wrong direction, just my opinion...

i read this because i sensed and angel densetsu concept but this was a great disappointment. the art is clear and good but the author emphasizes an event in this manhwa and gets the reader hooked into it and hooked onto it but then drops is at the last minute which gets annoying after a while. It had great potential but it failed in the end. i only gave it a 7 because the martial arts is good enough to make up for some of the failure.

The ending is a disappointment... These series has great fights, but that's all there really is. The plot development is mediocre and the whole premise of the manga disappears by the end.