African Iris アフリカン・アイリス
My friends, thank you for taking the time to identify this flower!
This is an uninvited flower, i.e., a kind of voluntary flower (seeds?) from somewhere to my front garden and backyard by winds or birds. Uninvited but a beautiful flower! Whatever the reasons for coming to see me, I appreciated "her" presence (^^). After your quick responses and helpful hints, I have surveyed some flower and plant books on the Internet.
As a result of my humble research, I have concluded that this is surely an "iris." So did many of you!
According to the Internet information, California is a famous land of "iris," which has so many varieties in the world; and, especially, they call various kinds of iris grown in the land of California "Californian iris" or "Pacific Coast iris." But I couldn't find out the exact flower type in the list of Californian irises. All of a sudden, however, I noticed an image which is very similar to my iris. It's called Not Californian but "African" iris. Yes, this is African iris!!!
The first one is my African iris and the second is from https://homeguides.sfgate.com/grow-african-irises-38818.html?fbclid=IwAR160nY-ZKEVmZbLKGRG8t3UyifRefUqFSkdcVQO5elwb8QDnFm_ARko0xk