The real cost of a month in Japan is always higher than the budget travel forums suggest, so let me give honest numbers from a frugal 3-week trip.

Flights: $540 round trip from Los Angeles on Korean Air via Seoul. Incheon layover was long enough to leave the airport and eat dakgalbi, which was a bonus.

JR Pass 14-day: ¥50,000 ($330). As I've detailed elsewhere, this was roughly break-even for my itinerary. Not a money-saver but not a ripoff either.

Accommodation: Average ¥4,200/night ($28) for the 21 nights. Mix of capsule hotels in Tokyo (¥3,500-4,500), a traditional guesthouse in Kyoto (¥6,000 — worth it once), and manga cafés as an experiment (¥1,800 for 8 hours overnight in Tokyo — genuinely fine, shower included).

Food: Average ¥2,500/day ($16.50). Japan is cheaper for food than its reputation suggests if you use convenience stores (7-Eleven onigiri at ¥130, hot food at the counter), standing ramen at lunchtime (¥700-900), and set lunch menus at restaurants (most sit-down places have teishoku sets for ¥900-1,200 at lunch).

Total for 21 days: approximately $2,100. That's about $100/day. Japan cannot be done on the Southeast Asia budget. But it's not as expensive as the internet suggests if you approach it intelligently.