Luigi is walking around the Boathouse, thinking of another way to get a Shine Sprite.
Luigi: Hmm... It's been a few days since we went to Noki Bay. And I think it's about time to clean it. Mario, wake up.
Mario wakes up from his nap.
Mario: Yeah, Luigi?
Luigi; Whatta you say we head to Noki Bay?
Mario: It's been a week since we've gone there. Let's get it cleaned up!
The Mario Bros. run to the glow on the Shine painting on the ground and look in the sky.
Bros: AAAAAHHH!!! MY EYES!!!
They open their eyes and see themselves in Noki Bay.
Young Noki: Mario! Luigi! Oh, I can't believe you're finally going underwater! Grandpa's waiting for you up top. Oh, don't forget to wear these.
The young Noki gives Mario and Luigi the scuba diving helmets.
Young Noki: You can use this rope as a shortcut to Grandpa.
Mario: Thanks, kid. Hey, what's your name?
Young Noki: Just call me Nok.
Mario: Nok?
Young Noki: It's short for Noki. That's not my name though. My nickname.
Mario: Let's go, Luigi.
The Mario Bros. use the rope and then do the rest of the climbing. Finally, they get to the old Noki.
Old Noki: Hello, boys. Apparently, my grandson already gave you your scuba diving helmets. Now, for what's really making the bay a mess: a giant eel! It's got cavities in its teeth and bacteria's gone all over the bay. There's a gap from where it's coming from that you can use as an entrance. If you clean its teeth, it'll leave for sure. Trust me. Now, both of you, gain your courage and dive right in.
The Mario Bros. jump off the cliff.
Mario and Luigi: COWABUNGAAAA!
They fall into the entrance.
Mario: Woah.
Luigi: This is weird.
A giant eel named Eely-Mouth rises and opens its mouth, as if it wants the Mario Bros. to fix its teeth.
Mario: Let's get these teeth clean!
Luigi: But we're not dentISTS!
Eely-Mouth is sucking Luigi in as if it's growing impatient.
Luigi: AAH!!!
FLUDD2: Luigi. Use my Hover Nozzle. It will be just enough power to escape.
Luigi does so, but the water used for the hovering gets on one of the bacteria-infested teeth, cleaning it.
Luigi: Oh, so that's what we have to do! It's so sparkly!
Mario: Luigi, we gotta clean these teeth now. Sparklies are for later!
Luigi: But it's so shiny!
Mario: Luigi!
Luigi: Fine.
Mario and Luigi both clean the teeth on different sides.
Luigi: Hey, Mario, this one is really dirty!
Mario: That's its golden tooth!
Luigi: Oh.
Soon, the Mario Bros. have cleaned all of Eely-Mouth's teeth and it starts to float away.
FLUDDs: Be sure to remember to clean your teeth properly from now on!
Eely-Mouth spits out its golden tooth as a thank you gift to the Marios. It also gives them a Shine Sprite. Mario grabs it and does the Shine Dance.
Mario: Yahoo!
Luigi: Onto the next Shine!