The Princess Diaries, Volume III: Princess in Love

In this volume, Mia struggles to decide how to break up with her boyfriend Kenny. In The Princess Diaries, Volume II: Princess in the Spotlight Kenny, Mia's biology partner at school, sent anonymous love letters to Mia expressing his feelings for her, resulting in Mia and Kenny dating. Mia does not love Kenny, but cannot bring herself to break up with him. Mia likes Michael, her friend Lilly's older brother, and feels she is leading Kenny on.

Mia begins to send Michael anonymous love letters, similar to that of Kenny's. Unknown to her, Mia's friend Tina, whom Mia confided in about the letters, has told Lilly about said letters. Lilly eventually tells Michael that it was Mia sending the letters. At the school Winter Carnival, Michael shows her a message on his computer revealing he knows she sent the love letters, and he returns her feelings.

Mia, not knowing how to respond and thinking Michael may be playing a joke on her, runs from her chair. Mia runs into Kenny, who mistakenly believes Mia is in love with Boris, and they break up. Mia returns home, is devastated and does not want to go to the dance following the carnival, and decides to move to Genovia. Mia's grandmother convinces her to go to the dance, where Mia sees Michael, and they share their first kiss together.