European electrical devices

I'm from Europe (plugs are 220 V) and I wonder if my electrical devices (mobile phone charger, hair dryer, hair straightener etc) will be functioning in Japan. Should I buy a converter instead?

Kiken,

Items such as hair dryers may work off the 100 V mains supply, but at half power or not at all. However, larger hotels sometimes have a 220 V outlet (for two-prong plugs) in the bathroom which you can use (with a plug adapter as necessary).
Your mobile phone charger will work if it is marked as being compatible with 100-240V.

Thanks for the information. I searched my mobile phone charger and didn't find any mark saying it's compatible with 100-220 V and I'm not going to stay at a big hotel, so I guess I'll buy a converter just to be on the safe side.