SOS Tokyo Metro Explorers The Next (2007)

Summer 2006 A 5th grader Ryuhei discovers a notebook entitled Tokyo Exploring Records It was a journal kept by his father Shohei when he was around Ryuheis age Ryuhei forms his own exploration party with his friends Shun and Yoshio One summer day the party and Ryuheis younger brother Sasuke who happens to tag along heads to the dungeon looking for a treasure indicated on the journal