1 Day Walk in Osaka Castle, Osaka, Japan. Osaka Castle is such a huge place where you can spend a whole day. Especially, it has a huge shopping mall, Q’s Mall, to the south, and if you can make use of Osaka Metro, you can get to Namba or Osaka Station Area in 10-20 minutes. Tanimachi 4-chome Station is the best to get there, as you can avoid all the steep slopes. The 2nd best is Morinomiya Station. Don’t use Osakajokoen Station to get to the castle tower, as it’s the most hectic station to reach