Even for Sousuke (aka Mr. "Once again, I have no idea where you put all of that stuff"), an acetylene torch in the locker seems a bit over the top. The amount of plastic explosives required to destroy the lock would have been small enough for even few notebooks pressed up behind to help shield him from the worst effects of the blast (it just might have left him with yet another scar).

And while it is a cute story, why would Kyoko be surprised at Sousuke's scar collection to begin with? Wouldn't she have already gotten a good look at it (along with a few photographs) that time they all went to the beach together?

As usual, I loved it! I can't say I've come across one of your stories that I disliked.