To avoid looking like she forgot Chiyo's birthday, Sekine is forced to use a "forbidden" psychic skill that causes her to temporarily gain weight so she can sky-write a birthday message. Character Developments
The episode emphasizes her role as the "straight man" of the group, burdened by knowing everyone else's secrets while struggling with her own social standing. 4-nin wa Sorezore Uso wo Tsuku - Episode 3 discussion 4-nin wa Sorezore Uso wo Tsuku Episode 3
A flashback reveals that the four girls didn't initially bond out of pure friendship. Sekine, using her psychic powers, originally charged fees to help her classmates—including Tsubasa—avoid trouble with teachers. To avoid looking like she forgot Chiyo's birthday,