is not just a calling device, game console, and PDA but also a
friend because it brings them fun, relieves their exhaustion and
anxieties, and makes them feel safe. ‘‘Withdrawal’’ involves being
impatient, fretful, and intolerable without a smartphone, constantly
having one’s smartphone in one’s mind even while not
using it, never giving up using one’s smartphone, and becoming
irritated when bothered while using one’s smartphone. ‘‘Cyberspace-
oriented relationship’’ includes questions about the feeling
that one’s relationships with his/her friends obtained through a
smartphone are more intimate than his/her relationships with his/
her real-life friends, experiencing an uncontrolled feeling of loss
when not able to use one’s smartphone, and consequently
constantly checking one’s smartphone.