Like the R Season, Sailor Stars is divided into two arcs: The first arc (also filler) solves some conflicts from the SuperS season, and also sees the return of the Outer Senshi, Haruka, Michiru, Setsuna, and Hotaru (now reborn as a child). The second arc is the actual plot from the manga. Usagi bids farewell to Mamoru, who is going to America to study abroad. In his place comes the Three Lights, an idol trio consisting of three boys, Seiya, Taiki, and Yaten. The new enemy is Galaxia, a woman who desires to rule the entire galaxy by collecting the Star Seeds of humans. Three new Senshi appear, the Sailor Starlights, who also intend to stop Galaxia without Sailor Moon's help.

SuperS centers heavily on Chibi-usa and the Sailor Team. A new enemy, the Dead Moon Circus, has now appeared. Their motive is to find the Golden Dream Mirror that would be used to rule the world. To do this, the enemy attacks innocent victims for their Dream Mirrors and test their energy. Chibi-usa also has a new ally on her side, Pegasus. This season also sees the Sailor Senshi obtaining new powers.

High school student Makoto Itou first notices Kotonoha Katsura at the start of his second semester, freshman year. Immediately, he becomes entranced by her beauty, but his bashfulness doesn't allow him to approach her, even though they ride the same train every day. Instead, he snaps a photo of her in secret and sets it as his cell phone's wallpaper: a charm that, if kept under wraps, would supposedly help you realize your love. However, classmate Sekai Saionji spots the picture, but instead of ratting him out, she offers to help set him up with Kotonoha—going so far as befriending her just for him. Thus, the trio begins a rather impromptu friendship. School Days follows the lives of these three teenagers as they traverse the joys and hardships that come with being a high schooler. In a story alive and brimming with romance and melancholy, the tale of these three students will linger in memory long after the momentous conclusion. [Written by MAL Rewrite]

It is widely believed that science can provide rational explanations for the countless phenomena of our universe. However, there are many aspects of our existence that science has not yet found a solution to and cannot decipher with numbers. The most notorious of these is the concept of love. While it may seem impossible to apply scientific theory to such an intricate and complex emotion, a daring pair of quick-witted Saitama University scientists aim to take on the challenge. One day the bold and beautiful Ayame Himuro outwardly declares that she is in love with Shinya Yukimura, her fellow logical and level-headed scientist. Acknowledging his own lack of experience with romance, Yukimura questions what factors constitute love in the first place and whether he is in love with Himuro or not. Both clueless in the dealings of love, the pair begin to conduct detailed experiments on one another to test the human characteristics that indicate love and discern whether they demonstrate these traits towards each other. As Himuro and Yukimura begin their intimate analysis, can the two scientists successfully apply scientific theory, with the help of their friends, to quantify the feelings they express for one another? [Written by MAL Rewrite]