>>3013369super easy. most places they weren't locked, even at night and in busy sections like shinjuki and shibuya. people there are super polite and non-confrontational so if you even happen to see anyone just smile, nod, wave, and dont cause trouble or be loud and nobody will do anything.
and i guess i shouldnt call them fire escapes as most of them seemed like the main means of entrance to the upper floors. more like 'external staircases'. an american equivalent would be like what you'd find at a motel, only 6+ stories instead of 2.