"We came up with a bag that changes its shape in accordance to what it holds inside," said Nendo, which has also launched a suitcase with a rolling fabric lid.
At its full length, the bag's large central pocket has enough space inside to store A3 drawings flat.
"In the extended form, the bag holds a full-size A3 drawing as well as samples with quite a bit of length," Nendo said.
A more compact shape can be created using poppers at the corners, which hold the two sides in place when folded in half.
In this form, the bag can carry A4 sheets in each side, as well as rolls of longer drawings, books, or material samples through the middle.
The two handles can be folded into the front pockets so when both sets are tucked away, the bag can be carried as a document holder.
"When features that were inspired by the convenience for the architect are introduced to daily life, it may generate an entirely new way to use bags," said Nendo.
Tod's signature stripe motif runs down the front of the leather bags, which are available in a range of subtle hues including black, grey, blue and tan.
Dezeen Book of Interviews: Nendo founder Oki Sato features in our new book, which is on sale now
The bags are installed as part of a window display at the brand's store on Via Spiga in Milan, arranged to show the different functions next to a set of draughtsmen's tools.
Graphics found on the implements – which inspired Nendo's latest range of watches – are printed onto the glass and the backdrop, along with scale drawings of the accessories.
Nendo founder Oki Sato revealed that his studio is working on more architecture projects in an interview with Dezeen during Milan design week, when the studio exhibited over 100 projects created in the past year.