Despite being a vert technologically advanced nation it is maybe somewhat surprising that Japan hasn’t taken the use of credit cards to their hearts. It is still very much a cash based society which means that people carry large(ish) amounts of money on them at all times. Yet in spite of this, there is very little crime and theft. In fact I often walk along the street counting my money without a care in the world. Very little risk is involved in doing this unlike in other countries where you’re likely to get mugged. Maybe I will one day when I’m no longer in Japan (when that may be I don’t know!) I recently had to carry a large amount of cash but I never really got nervous about having this on me for a few days.
On the subject of money the Japanese are very respectful of it and always pay other people via an envelope containing the funds. You can also bet your life that all these notes will be crisp and new-like as all money appears to be here. A far contrast from the crumpled up, torn and graffitied notes you may get in the UK.