Kyosera Dome Osaka (wikipedia)
Seats: about 48,000 (depends on the layout of the arena seats)
Stands seating chart (Japanese) / Official Site
Arena – varies, see more info here
Access:
JR Taisho Station (Osaka Loop Line). About a 7 minute walk. Once leaving the ticket gates, follow the signs to the Dome.
Nagahori Tsurumi-ryokuchi Subway Line - Dome-mae Station. The Dome is right outside the exit.
Hanshin Namba Line - Dome-mae Station. The Dome is right outside the exit.
Chuo Subway Lines - Kujo Station. About a 10 minute walk.