Shin SOS Dai Tokyo Tankentai
Other name:
SOS! Tokyo Metro Explorers: The Next, 新SOS大東京探検隊
Genres: Adventure
Status: Completed
Summary:
"While packing for a move, elementary school student Ryuhei finds his father's old school notebook detailing a search for a treasure in Tokyo's vast network of underground passages. With his little brother tagging along, he and three friends from an online chat room gather and set out on a quest to find the treasure. What they discover instead is an entire underground community composed of assorted eccentrics, including a senile old soldier still performing a World War II-era mission."