Clean the West Bell
From the Super Mario Wiki
Clean the West Bell, also called Belltower Clanging 1, Ring My Bell, and The Dirty Bell, is a mission in Delfino Plaza in Super Mario Sunshine. It is available from the start, and involves cleaning the bell in the tower at the southwest corner of Delfino Plaza. Although the most direct method of reaching the bell is by using F.L.U.D.D.'s Rocket Nozzle, it is possible to use the Hover Nozzle to fly there from the nearby rooftop. After reaching the bell, Mario must spray it with water to clean off the black goop. It is also possible to hit the bell with water from the nearby rooftop (assuming that the angle is correct), and therefore it is not necessary to fly directly there. After consistently spraying the bell for about twenty seconds and fully cleaning it, a Shine Sprite appears. It then flies inside of the tower, and it can then only be reached by entering a nearby Manhole and navigating the sewer systems. Once Mario reaches the bottom of the tower, he can jump up and grab the Shine Sprite.