In many locales it's common enough to see a lost mitten or other small item placed on a fencepost for the owner to reclaim.
In Tokyo this kind gesture is taken a step or two further: find a protective plastic bag, some packing tape, a scrap of paper and a marker to make a handmade sign reading " LOST ITEM," then post your package near where said item was found. The child's shoe here was found hung on a residential street near Nippori station. Sadly a week or so after this photo was taken and the owner had not yet returned for it. Anyone missing a little pink shoe?
Also lost/found in this neighborhood were a frilly black broken parasol carefully draped over a rail, and a tiny sock with cherries printed on it, perched on a tree branch.