During exactly what dates of the year can the Centaurus constellation be seen from Tokyo, Japan? And what is the ideal date for viewing it from Tokyo? I found on a website that it can been seen May-June in New Zealand, best visible at 21:00 (9pm) during May and that the midline is May 20th.
(According to the Japanese Wikipedia page for Centaurus, only from Okinawa can the entire constellation be seen; in Tokyo, apparently only part of it can be seen.)