we are thinking of buying tent and sleeping bags for camping ,can anyone suggest a good place with some choice at reasonable price.

family auto camping a home center like Canniz Home ( all over the suburbs)

you are a bit late into the season though so move quick. Costco had great stuff in spring

serious tents.....North Face at Odaiba or a serious hikers store ICI (??) at Shin Okubo station, go out the gate and turn right and walk 100meters on the left hand side.