It's not that Rei tries to make the others forget her birthday. It's just that it's much easier to refer to the day as another regular day, easier to redirect the conversation from her and birthdays to someone else, to any other holiday instead
"I want to see the cherry blossoms again," Minako says. "We already did," Rei cuts in without looking up from her schoolwork. "In Sendai."
Valentine's Day is coming up but Rei notices Minako isn't as excited this year - so she decides to do something about it.
For all her disdain for crowds, Rei actually looks forward to hatsumode at the shrine. (A short slice of life of new year's day at Hikawa Jinja.)
It's in the middle of one of their totally-studying-pillow-fight-tickle-torture-dogpiles when Usagi has a flashback. Rei notices first, hears a choked sound, sees the utter terror in Usagi's eyes, and immediately rushes to pull everyone off of Usagi. (Scenes after the Petite Étrangère musical, which covers the Black Moon arc)
A series of "Five times …" one-shots, centering mostly around Minako. Also features Minako/Rei; updated intermittently.