Japan : Question about japanese writing on shirt?

Question:

http://www.amazon.com/Lucky-Star-Vol-2-L…

what does it say on the shirt

Answer:

Agreed on the 6-3 Izumi.

I also haven't seen the show, but it looks like a sports uniform for a school student. If that's the case, the 6-3 would represent the student's grade (6) and class within the grade (3), and the kanji would be the student's name (probably family name). By the way, if I'm right about this, the character would be an elementary school student. 6th grade in Japan is the last grade of elementary school, and both junior and senior high school are three years long, with grades designated 1-3 at each level.