I have been seeking out Tokyo's best bars long enough to have accumulated a fair-sized database on the subject. Even so, for the best part of a decade, a search with the keywords safe + sane + fun + Roppongi have turned up zero results. By safe I mean you don't have to watch your purse. By sane I mean you can talk to the person next to you without shouting. By fun I mean the person next to you would be someone you would want to talk to. And by Roppongi I mean within the first few blocks that hug the four corners of the crossing.

With the discovery of Kun-pu, I have finally found my haven. (Though next time I might also factor in cheap, which Kun-pu isn't; the seating charge at the bar is ¥800 per head.)

This is an establishment that spans two floors, with a restaurant on the second floor and a bar on the third. The former is exempt from the charge and always full, thanks to the chef's flair in the kitchen. But the latter, even with the charge, is well patronized till sunrise.

The decor on both floors is uniquely modern-traditional, blending both new- and old-school elements of Japanese interior design. The floors are unadorned wood, like those found in a temple or dojo. The walls on the restaurant level are made of textured red mud, like those found in ancient Japan. Upstairs they are a uniform matte black — so matte and so black, in fact, that the stainless-steel paneling surrounding the open kitchen area reflects no light at all; it can only bounce back more black.

There are two private rooms at one end of the bar level, separated from the main room by stylish sliding doors. Between the rooms themselves, dramatic red mock temple doors can be removed if necessary to make one large private room.

But nothing underscores the contrast of old-meets-new like the toilets on the bar level. One has a pebbled floor with large stepping stones; the other has the pebbles concreted into place, as is often seen in the entry of a ryokan (Japanese- style traditional inn), and the walls stripped with bamboo. The initial visual message is quaint, but as soon as you enter, the toilet seat automatically opens and, similarly, motion sensors activate the flush and close the lid.

While customers crowd around tables downstairs, the bar upstairs revels in space. A long and wide no-frills L-shaped counter runs the length of two walls. On the side opposite the private rooms, the counter even backtracks to form an island around one end of the open kitchen.

But the real draw is at the other side of the L, where a couple of plate-glass windows have been cut out of the matte black to afford soothing leafy views of the park across the street. It is the perfect place to sit in Kun-pu, which means "fragrant breeze." I guess the people sitting cheek-to-jowl in the restaurant downstairs must be unaware that you can also order food at the bar.

One of Kun-pu's specialties is to toss a Caesar salad or carve a risotto within a massive round of Parmesan cheese that sits on the bar, right in the crook of the L. And your cover charge gets you a selection of seasonal Japanese-style tidbits served on a small elegantly curved ceramic platter. I received one small dollop each of mushroom, pork, mizuna greens, tofu and tomato, which had been variously marinated, pureed or teased in some way to please the palate.

And speaking of beer, though Kun-pu offers only Asahi on tap, each time you order one it will be served in a different "glass." After receiving your first one in an almost-typical pint glass, just heavier, like an oversize tumbler — you will never be served in the same type of receptacle twice. My second beer came in a beautiful long-stemmed wine glass, a standard choice for the second, I'm told. But after that, it's anyone's guess. A huge heart-shaped glass like a vase might be next. Or a giant stein shaped like a dinosaur's foot. Or a glass with hollow cartoonish feet. In short, anything that will hold a half-pint or pint is fair game. One of my friends had so many beers that he ended up with a gravy boat from the kitchen.

The staff have no end of fun pandering to this idiosyncrasy of the house. In fact, they are encouraged to do so. Kun-pu's motto, printed on every coaster, translates as, "If you can laugh, you are happy."

A few toys are on hand for the amusement of both staff and customers. These include one of the smallest kendama (ball and stick) games I've ever seen, and are revealed by the staff if and when it seems appropriate. Reading the mood of each individual or group of customers is obviously something these boys are required to do, and they have the freedom to serve the customers they click with, rather than being assigned to an area.

Maybe their paychecks are the final destination of that ¥800 surcharge and they can afford to laugh. But you can't buy personality; you've either got it or you haven't, and at Kun-pu, it is abundant.

Kun-pu; 4-8-3-2F/3F Roppongi, Minato-ku, Tokyo; tel. (03) 3404-3408, (03) 5772-3279. Opening hours 6 p.m.-1 a.m. (2F), 6 p.m.-5 a.m. (3F), both closed Sundays and holidays. Service charge ¥800 (bar only). Drinks from ¥800, food from ¥1,000.