adviceS: Dial-up in Tokyo & greater Kanto?
Question: Using an antiquated laptop with a serial modem port is there a free or inexepnsive dial up service in Tokyo area?

Do you LIKE getting reamed in your hinterlands by NTT?

For a modest 20-30 minutes a day connection time to NTT for checking email and news, dial-up will cost you much more than 2,000yen/month.

Flat-rate ASDL at 1,500yen/m like Yahoo BB will save you a lot of money. If you live WAY out in the boondocks where ADSL doesn't work, old ISDN modems from NTT are dirt cheap(free?) and flat-rate is 1,200yen/m or less. I use "bonded-pair" IDSN out on my rice ranch in Shikoku that provides 256k speed (two ISDN lines, 128k + 128k) because ASDL is impossible in my Jomon village.

Your PC card slot will allow you to try WiFi or most modern ASDL and LAN-type services.

For more about low-tech 56k and ISDN modems services (as well as ASDL) read this truely definative source:
ISPs in Japan FAQ , by Keith Wilkinson (2003 info)