While cleaning the café, a woman approaches Ichigo and Lettuce and begins speaking to them in English (Spanish in the 4Kids dub), but they cannot understand her. Masaya appears and translates for them. The woman, Mary McGuire (Maria Rivera in the 4Kids Dub), is a pianist who Ryou asked for a performance at an upcoming formal party to reward the girls for their good work. During the party, Kish appears and uses a new technique to steal Mary's (Maria's) spirit to create a chimera anima. During the battle, he mentions the name of the mysterious alien leader, Deep Blue. The girls use Mary's (Maria's) music to weaken the monster, enabling the girls to defeat it and return her spirit back to her body.

Masaya takes Ichigo to Inohara Park to show her a large cherry tree that is unusually blooming out of season. The next day, Keiichiro discovers that five cherry trees have been infected by the aliens explaining the early blooming. The Mew Mews set out to destroy them simultaneously, or the trees will release a poison dangerous to Tokyo. Mew Ichigo takes the tree in Inohara Park, where Kish waits for her. A fight keeps Ichigo from attacking the tree, and it begins releasing its poison. Ichigo jumps into the tree and successfully destroys it. After Kish leaves, Mew Ichigo finds Masaya standing behind her after he called out "Ichigo".

Mint has a strange dream in which she is talking with her merged animal, the ultramarine lorikeet. Later at the café, Ryou and Keiichiro tell the girls about a substance called mew aqua and its power. After her dream, Mint is concerned about their mission. When she learns the late-arriving Ichigo was on a date with Masaya, she gets angry and stomps out of the café. Later the girls receive a package with Mint's pendant and uniform in it. Zakuro goes to talk to her while the others begin searching for mew aqua. The aliens are also searching for it and find it just as Ichigo, Lettuce, and Pudding appear. Kish merges five parasites into the mew aqua, creating a powerful new chimera anima. The girls are struggling to fight it but Mew Zakuro is able to convince Mint to transform and together they defeat the monster. They learn the mew aqua was a fake and Mint apologizes to Ichigo for her earlier actions.

Ichigo meets a lonely girl named Momoka whose parents are always busy. Ichigo learns she is a fan of Zakuro, so she tells Zakuro about the girl. Zakuro later runs into the girl at a restaurant. Momoka is upset at learning her parents have cancelled their dinner plans, but Zakuro assures her that her parents still love her and invites the girl to have dinner with her instead. The next day, Momoka's parents send her a beautiful pendant that Kish believes is made of mew aqua. When the daycare holds a family picnic, Momoka's parents do not show up and the upset girl runs off. Along the way, she loses the handkerchief that Zakuro gave her. Kish offers to help her, if she gives him her pendant. Zakuro arrives to help her, but is entangled in some vines by Kish. After realizing the pendant contains no mew aqua, Kish leaves. Zakuro returns the handkerchief and pendant to Momoka. Her parents arrive for the picnic, and Zakuro feels certain they will not leave her alone again.

The aliens decide to use special chimera animas to release pollutants into Tokyo Bay. The Mew Mews arrive, sans Lettuce, and find themselves having to fight numerous smaller chimera animas made from fish. Mew Lettuce and Ryou arrive by boat, but the larger monster destroys it and they are thrown into the water. While the others defeat the fish monsters by combining Mint and Pudding's attacks, Lettuce tries to save the drowning Ryou. Her emotions activate the mew aqua around his neck, causing her legs change to a porpoise fin and easily bring Ryou back to the surface. The mew aqua weakens the remaining chimera anima, enabling them to defeat it.