i think the duet was on "Love Love Aishiteru" (KinKi Kids show before Domoto Kyoudai), not "Ayu Ready?"
i think it's in the Ayu Downloads section if you search for it. dunno if it's subbed though.
actually, i thought the duet was. not so good, LOL. i think "SEASONS" was to high for them to sing. but, i do LOVE the performaces Ayu did with the Domoto Brothers Band on Domoto Kyoudai. she always performs so good on the show! (STEP you & Together When... were really great!)