Equipment malfunction May 13 on the Metro Chiyoda Line led to a rolling stock substitution, with a 16000 series making a midday run to Hon Atsugi. After terminating there, it ran out of service to Isehara, where it turned back via a crossover, returning to Hon Atsugi for the next up service. This is apparently the first time Metro stock has done this in daylight hours, typically these are only seen on this stretch of line in the nighttime.