Sakura Nankyoku is a total otaku. Due to a fluke, she gets elected as her class' Student Council President. Everything takes off from there into a series of crazy misadventures revolving around Sakura, her family, and her classmates.

Asami Onohara is a seventeen-year old high-school student with a secret which has not been revealed to anyone: She is already married. Her husband, Kyosuke Ichimaru, is a Physics teacher in the same high school as her. However, even though they are officially a married couple, Asami's father forbids them to have any sexual contact until after Asami has graduated. Asami has to hide the fact that she is married to Kyosuke while trying desperately to further their relationship, and it does not help when there are so many interferences and obstacles from her father and other third parties.

Momoko, who attends a special school, is both mentally and physically disabled. Every morning she becomes peevish because she can't go to the ordinary school with her twin brother Riki. Her family soothes Momoko by singing her favorite song "The Song of Frogs." One day, Momoko shouts encouragement to Riki who's playing dodgeball at an open classroom day and Riki's team wins the game. Ryuji, whose team lost the game, is not impressed and demands that Riki stop bringing his 'idiot sister' to school. Riki totally loses control and hits Ryuji with all his might. The following year, an experiment in integrated education is implemented and Momoko begins to attend Riki's school. Unfortunately, her physical condition takes a turn for the worse and she's sent to a hospital. Riki and all her classmates want to cheer her up and they set a goal of winning a relay race so that they would be able to tell Momoko the good news. Meanwhile, the fastest sprinter, Ryuichi, insists that he won't be taking part in the race.

The third season of Kimi ni Todoke. What do you do once you're a couple? Although she struggles with her blossoming feelings, Sawako comes to terms with herself and tells Kazehaya how she feels about him. Attracted by Sawako's unnoticed efforts and genuine personality, Kazehaya also candidly makes his feelings known. Thus, their new relationship begins. Their first date, their school life together, joy, embarrassment and new struggles — everything is fresh and new as the couple awkwardly and gradually learns more about one another, all while their friends' love stories begin to take shape as well. This bittersweet and poignant story of young people, woven from their romantic feelings and dear friendships, begins once more.