The times when Shizuka smiled:

Genuine:
- when she was with Chappy
- when Takopi helped her deal with school and bullying
- when Takopi killed Marina
- when hanging out with Azuma and fake Marina
- when going on Tokyo trip
- when she was about to see her dad and Chappy
Performative:
- when she saw Azuma in terrible state after him failing to steal the ring
- when Azuma proclaimed he'll do anything for her
- during reunion with Azuma in high school