Touta Matsuda is Mr. Yagami's right hand arm, man. He's Mr. Yagami's everything. His confidant. His best friend. His silly rabbit. His silly rabbit. Does he call him that? No.

In Love Note though, Matsuda is Soichiro's apprentice. A genius in deduction with a sharp mind that rivals even that of L's. The only thing holding him back is that he's a complete idiot in every other way. Where Light is Smart but Dull, Matsuda is Dumb but Sharp. He is wholly dedicated to the Kira investigation, of course to save the world, but also because he idolizes L as the greatest mind of the time. 

For voice:

Don't be afraid to add your own twist, but generally I'm looking for something a little goofy; more cartoony than anime if you catch my drift. I have no specific voice in mind other than perhaps a bit higher pitched, so I look forward to seeing what you bring to the table.