Inexpensive, but you get what you pay for!
First, the "cocoons"… when I booked, my reservation simply said "a room"—no further details! So, imagine my surprise upon arrival to find it was actually a bed in a dormitory—a "cocoon"! "Cocoon" isn't a standard term for a dorm; in Japan, they use "capsule," but I’d never encountered "cocoon" before.
I had noticed the term on the hotel’s webpage, but the fact that the booking specified "a room" put my mind at ease. Not the case at all!
As for the rest… It’s not easy to find, though manageable. The stairs are very steep—like those in the Netherlands. The "cocoon" has a very low ceiling; if you’re over 1.75m (approx. 5'9") tall, you’ll struggle to sit upright—something for taller guests to keep in mind. You have to make your own bed; there are no actual sheets, just duvet covers that serve the purpose. You get small towels and a tiny secure locker, but nowhere to store a suitcase! The lights stay on all night, so don’t forget to bring an eye mask! You’re given a key card for the door, but be careful—it demagnetizes very easily! And, naturally, the staff isn't always around—there’s no one there in the morning and late at night !
So, it’s cheap, clean, centrally located, with staff who are helpful enough—but nothing more—and clean restrooms.
In short: it’s inexpensive, but that’s about it. A solid 3–4 out of 10!