I really love the concept of The Chapter Four. The Chapter Four starts on the 4th of each month and runs for two weeks following. There are four sections of this event, each with a different sale (gacha, 2 for 1, half off, and under 100L).
Lunaricon has a gacha called “Gamer Girl” at the event, at 25L per play. The have cute video game inspired tights and slippers. The new TCF starts on July 4th.