It was bugging me that the other release called that dropped item a 'wallet', though there are some rather slim wallets out there.
A 'passholder', especially given Japan's public transportation infrastructure, makes a lot more sense.
Black Cat scans are way better than Btooom. Black Cat are proven to be reliable and accurate, unlike the other group. I wonder why they're even bothering to scan something that a group already picked up.
Other than expanding on Sumi and presenting all her thoughts it seems to also go into more details of their line of work than the main series did, interesting.