For city riding, be on the eye-out for cyclists flip-flopping between the road and the pavement. If you find yourself riding alongside or even worse behind someone who's on the pavement, be wary.
Aside from that. the aforementioned taxis - generally can be fine but be vigilant for people flagging them down (a taxi may swing left in front of you suddenly) or taxis stopping (ditto for pulling over, but with less obvious visual clues).
Basically, be vigilant and you'll be fine. It's a big city chock-full of vehicles - ride in a way which is assertive, yet defensive. Don't allow yourself to be squeezed into the gutter. I ride a good metre from the kerb out and rarely, as in hardly ever, get honked.
If it's not a bling bike and you chain it up with a decent lock to a solid object like a steel fence you should be alright. I ride my bike to a bike club meeting (Half-Fast Cycling) in Roppongi every month and park it out in the street. I haven't heard of anyone in the club having had a problem yet.
I think the most common type of bike stolen are mamachari, by people who're too lazy to walk to/from the station. High-end bikes sometimes disappear to be sold for parts.
Devnull, when in Aomori are you, I am getting back into geared iding if you are keen for a group ride I can probably get two or three others. We are based in Hachinohe but it would be cool to go for a ride with someone else from time to time,------->>>>>>> family and work obligations not leaving a lot of it however. cheers
Sounds like my kind of riding. What bike are you likely selling? Might know a buyer if you are under 177cms or there abouts. Is there a charity ride to Lake Towada and back this year? Usually in September.
The frame/fork/headset I have on the forsale section, a 53cm Merlin Extralight. 1219 grams of drop dead gorgeousness on wheels I'm sending pictures to a guy tomorrow. If he doesn't want it, it is up for grabs.
Next week I'm doing a very slow imperial century from Misawa to Mutsu city and back, up the east coast and down the west. I'll be pacing my daughter, she is just getting started on distance. She did so well on a 100km mountain rambling last weekend that makes me think she's ready to enjoy a flat 100-miler. If you have time to kill you are welcome to join us. Besides that I have a few fun runs I like to do around Nambu, Towada, and the Hakkoda mountains. The weekend after the next would be good for Nambu, with plenty of apples and peaches for fueling.