"Young Boy"

Specialty: Big Swords

Strength 23
Dexterity 14
Speed 16
Constitution 16
Intelligence 17
Will 13
Charm 17
LP 10

If you are playing as Sara, Shonen can be picked up right after the intro.  Otherwise, if Sara is in your party while you seal the 4th Abyss Gate, she'll push Shonen out of the way and get taken into the Abyss instead.  If you don't get him there, you will be forced to take him into your party before entering the Abyss.  However, he does not get to fight in the final battle.

Shonen really isn't a playable character- unless you're Sara, you have to wait until you either seal the 4th Abyss or until he gets forced upon you.  He could be an amazing character with his high strength and skill with the Big Swords, but he can't fight in the last battle which really makes him not very useful...  If you're playing as Sara, you might as well get him and at least rob him of his Victory Katana.