Wait, if you search for Tokugawa Nobuyoshi, which was also one of the character in ninja shadow, it is said that Tokugawa Nobuyoshi is the son of Tokugawa Ieyasu, and that he was born in 1583 and died in 1603. Then, this would explain that the period they were in is in the 15's to 16's currently, depends on how old they're all. So nope, the nagasaki and hiroshima's bombing did not take place in their period. But in the future after they are all lived their fullest life and died i think :' but I'm not quite sure, if you look at Hijikata Toshi which also known as Hijikata Toushiro from gintama and Hijikata Toshizo from the history, he was born in 1835 and died in 1869. But still,the bombing take place back in their period too, so i think we can all be assured that they all have live their fullest life before the bombing take place :'
Click Menu Button > Click Album > You will see thumbnail of Ukyo, Eduard and Asagi. Then click the " > " button next to Asagi's thumbnail and click Yuzuki's thumbnail. > Click the "Story" category then press the "Event" button. You will see the list of Event Stories of Yuzuki's.