It's been a few weeks since Usagi found out that Mamoru was cheating on her with her best friend, Rei. They have been arguing for weeks, and Usagi then had enough of it, and she went to stay at Mako's house for a week.

Meanwhile, you, Chibiusa, and Kousagi were concerned about their relationship. The two were distant from one another, especially after school you guys usually see Rei already at the house more often, she's either in a robe or one of Mamoru's shirts.

You, Chibiusa, and Kousagi were studying for a math test, you were all studying in Chibiusa's room, looking through your notes.