Degree evolution of Long term banks and City Banks. Time evolution of the in-degree (red symbols) and out-degree (black symbols) of 3 Long term banks (B396 Industrial Bank of Japan, B397 Long Term Bank of Japan, and B398 Nippon Credit Bank) and 9 City banks (B10001 Mizuho Bank in 2011, B10002 Sakura Bank in 2001, B10003 Fuji Bank in 2002, B10005 Bank of Tokyo - Mitsubishi UFJ in 2011, B10006 Asahi Bank in 2003, B10008 UFJ Bank in 2006, B10009 Sumitomo Mitsui Banking Corp. in 2011, B10010 Resona Bank in 2011, and B10011 Tokai Bank in 2002. The degree refer to the FDR statistically validated networks. The time evolution is halted when the bank undergoes a merger with another bank. For details about the merging process see the main text.