[AKI]

It means 'fall, autumn'. It's finally getting chilly. Fall is the best season for sports, reading, eating, and etc. There is a lot of seasonal fruits in Japan. These days, you could get any fruits anytime from anywhere, but you should try it in fall. It's the best!

UN-DO NO AKI = Fall for sports (which means fall is good season for sports)

DOKU-SHO NO AKI = Fall for the reading