Just north of the hideout, you'll find your first treasure on a high column.
This one is on a rooftop just north of the previous treasure.
An Ancestor Door guards this treasure in the northwest of the map. To reach it, you'll have to use Sly's Archer costume and fire a rope arrow - the spot is marked as (3) on the map.
This one's also behind an Ancestor Door atop the waterfall. Use the Samurai costume to knock a fireball back and open the way.
You'll have to use both the Archer and Sabertooth costumes to reach this one - the starting point is marked as (5) on the map. Using these, you'll be able to reach the Ancestor Door far from the mapped part of the level.
This one's on a tall column just south of the hideout.
Head behind the geisha house to find this treasure atop a crate.
This one hides behind another Ancestor Door. To reach it, use the Archer costume's rope arrow from atop Riochi's sushi shop. Once across, you'll need to hop on the switch and use the Thief costume's Slow Time ability to get in before the door closes.
You'll find this on a crate behind the building south of the sushi shop.
Just south of the hideout are some low-altitude platforms. Drop down and use the Jailbird costume to knock the crates out of the way. Beyond is an Ancestor Door which holds another treasure.
This guy can be found on a boat in the eastern section of the map.
The final treasure is on a low platform just north of the hideout.