Yosuke.
Ding ding ding.
1. I like swords! - Offers you a sword, then says that he'd like to use it with the dagger he also offers you.
2. But daggers are better. After all, you can wield two of those at once! - Ends up using daggers as his weapon
3. Another battle? Man, alright. Just give me a sec to turn my music off, alright? - Wears headphones that he takes off before each battle
Other clues included:
4. I just hope they don't short-circuit. Electricity hurts! - Weak to Electricity
5. Ow ow ow ow ow! Man, not another bike! - Crashes them CONSTANTLY.
6. Agh! I promise, I'll buy you another copy of Trial of the Dragon! I PROMISE! - Breaks Chie's copy of it, right before she destroys him.
7. Heheh, I always knew I had a little ninja in me! It was just hiding behind the casanova, of course. - Jiraiya is his Persona, and the casanova bit is just a poke at him failing it up miserably with all girls ever.