Found items at Palaceside Building are generally held at the Disaster Prevention Center (security) (photo right). If you lose something, items with reports are stored there—enter the west entrance and turn left.
Items turned in mid-Nov to mid-Dec last year: 61 total—6 wallets, 9 phones (incl. smartphones), 5 commuter passes, two 100-yen coins, and unusually a 5-yuan Chinese note. Mid-Dec to mid-Jan: 62 items—8 wallets, 10 phones, 3 passes, 50 yen cash, 5 employee IDs.
Two months show the same trend—~2 items/day. Phones alone: one every three days. Fortunately wallets, phones and passes mostly return to owners—contact the Disaster Prevention Center if you lose anything here.
A MyNavi News survey of 600 smartphone members last year: 29 (4.9%) had lost phones outside; 23 (79.3%) got them back, 6 (20.7%) didn't—four in five were "saved!"
Where did they lose them? Top answers: "station restroom," "inside station," "on train"—7 of 29 at stations/trains; watch these spots.
Asked what worries them most if a phone is lost, 216 (36%) cited "personal data leakage" overwhelmingly.
US-Japan difference? Old data (Mar 2012): Symantec's "deliberately lost 50 phones" test in five US/Canada cities. Phones were trackable, but only 25 finders contacted owners. Of 50, 48 finders tried accessing owner apps/data—SNS, email, personal photos. ~40% opened online banking. Lost phone = leaked personal info.
Handy for frequent losers: the keychain "Cobra Tag" (photo left)—pricey but useful. Keep the tag in another pocket; Bluetooth links it to your phone. Beyond 10 m, the phone alarms. If you miss the alarm, GPS logs location. Drop both and you're out of luck.