Deposit Lockers at Kansai Int’l

Hi!, I'd like to find out if there are any lockers for depositing big pieces of luggage as I'll be arriving @ Kansai Int'l in the morning n my friend can only pick me up in the evening, so thinking of spending the day around the airport n Osaka Bay area.

You can use "Baggage Storage" service at the airport. See this page :
http://www.kansai-airport.or.jp/en/service/baggage/index.htm...

there isn't much to do in the airport for a whole day. To go to "Osaka bay" you will have to take a limousine to go there (d oyou mean Cosmo square , Aquarium area etc.?) and back to the airport. The airport itself is on an artificial island far from the "natural" shore where Osaka and suburbs are located.