Japanese reproductions of Levi's, Lee's or Wrangler's jeans are generally a fuller cut than the jeans from modern brands like Acne et al that guys like me are used to. For some, this is a problem, but luckily there are a few pairs that fit the bill if you're looking for slim cuts. Here is my list of slim or skinny Japanese jeans!
Skull Jeans are known for their more slim and modern cuts. If you're looking for jeans as skinny as Acne's Max or Dior's jeans, this is your stop. Their skinniest pair is the 5010. It is available in two types of denim, one is unsanforized shrink-to-fit denim that come in a one wash-state and the other one is a sanforized denim that can be bought raw and has a black leather patch.
Because of the different denim they are sized slightly differently, so look at the measurements to make sure you get the right size. You can also check out 5507 and 5109XXS(hair-on-hide patch), they are slim but not skinny cuts.
They also make fuller cuts and black jeans.
Gallery of used Skull's
Skull Jeans worn by skinny guy
Skull Jeans worn by a guy with big legs
The Flat Head
Next out is The Flat Head with its weird arcuate, a snake biting another snake or what? Anyway, the denim is awesome, similar to Eternal's, and the 3001 cut is slim.
You should be able to remove the backpocket stitching without leaving any trace behind if you don't like the arcuate. Also available in black as the 4001BK.
TFH 3001 fit
TFH denim jacket with the same denim
The 3005's also have the same denim as the 3001's
Fullcount only use Zimbabwean single-cropped(harvested once a year) cotton, which is probably the highest quality cotton you can use in jeans. Zimbabwean cotton is know for its long fibres and because it is single-cropped, it's allowed to grow even longer than cotton that is harvested more than once a year. This allows Fullcount to make denim of "only" 13.76oz weight that is as durable as other brands' 15 or more oz jeans.
Their 1108 cut is slim with a high waist, so you will probably want to size down if you're used to lower waists.
The same cut is also available in black(1310) and indigo overdyed with black(1474).
How they fit
Fullcount Online store
Samurai's slimmest pair is the S0505XX, which I own. You need only scroll down to find pictures of details and fit. You can order directly from Samurai and they have measurements for all sizes. The S0505XX's are almost sold out though, so you better hurry if you want a pair.
They also have other cuts that aren't quite as slim but can still be described as slim, the S5000VX for example.
S0505XX @ d-stock
S0505XX @ 2nd
S0505XX @ Izumi
S0505XX @ g-a-r-d-e-n
The SD-103 is a reasonably slim cut and again, scroll down for pictures. It is not quite as slim as the other cuts listed above though. They do have a huge advantage over the other brands; pigs.
SD Jeans Chart
The Eternal 811's are about the same fit as the SD-103's, except for the rise which is about 1" higher, maybe? The denim is awesome, 'nough said.
There is also the Eternal 846 and 851. They are the same cut, slightly slimmer than the 811's and 14oz instead of 14.5 like the 811's. The 846's are indigo dyed and the 851's are black.
They are Eternal's budget jeans, but the only budget thing about them is the single-selvedge. Unfortunately, the 846's are sold out most places.
Eternal 811 used
Other slim jeans to check out are the FOB Factory 151 (1, 2), Denime 66 Low-rise, Denime 805XX, plain 805, Dubbleworks 660 (1, 2). There are also a few other slim jeans from other brands, so if you don't like the ones I've listed you can have a look around for yourself.
If the jeans you're looking for are sold out at the stores I linked to, use rakuten, j-e-a-n-s.net or Google to search for them.
**Update: Added a couple more links. Check out the Dry Bones 570 too, thansk to keyko @superfuture for this one.
Update 2: FOB Factory 161