KDDI Corp. said Monday its “au” mobile phone services are experiencing technical difficulties across Japan, causing disruptions to calls and internet connections. The disruption began at 7:18 a.m. across 31 western Japan prefectures including Osaka, Kyoto, and Fukuoka before spreading nationwide, said KDDI, one of the three major carriers in the country. KDDI’s other mobile services such as “povo” and “UQ mobile” were also impacted, it said.