Unless one really needs a car on a nearly daily basis, the renting option seems very sensible. Living in central(ish) Tokyo I don't really miss a car. I've yet to hire one here, though there are occasions I think that I should at least have considered it in the past. We went on holiday to a bit of an out of the way place (a major tourist attraction for centuries, but still out of the way: Ise) and the local trains there were, particularly on a Sunday, quite infrequent. In Tokyo itself I find the trains to mostly have enough stations to be convenient and the timetable to be frequent enough. On my local overground line they run every three to five minutes until very late at night (and then every six or seven minutes) and the underground line is every three minutes during peak hours and every six to seven minutes at other times. Compared to what the traffic is like on the times others have driven me or when I take a taxi, I suspect the trains are at least as quick. When visiting some places in the outskirts or when being out very late there've been times a car might have been easier, but I've got used to relying on (and being able to rely on) the trains here. I should, however, be more willing to think about a hire car when travelling around.