Season
- Season 1 2022-10-11
Episode
- Episode 1: Episode 1
- Episode 2: Episode 2
- Episode 3: Episode 3
- Episode 4: Episode 4
- Episode 5: Episode 5
- Episode 6: Episode 6
- Episode 7: Episode 7
- Episode 8: Episode 8
- Episode 9: Episode 9
- Episode 10: Episode 10
- Episode 11: Episode 11
- Episode 12: Episode 12
- Episode 13: Episode 13
- Episode 14: Episode 14
- Episode 15: Episode 15
- Episode 16: Episode 16
- Episode 17: Episode 17
- Episode 18: Episode 18
- Episode 19: Episode 19
- Episode 20: Episode 20
- Episode 21: Episode 21
- Episode 22: Episode 22
- Episode 23: Episode 23
- Episode 24: Episode 24
- Episode 25: Episode 25
- Episode 26: Episode 26
- Episode 27: Episode 27
- Episode 28: Episode 28
- Episode 29: Episode 29
- Episode 30: Episode 30
- Episode 31: Episode 31
- Episode 32: Episode 32
- Episode 33: Episode 33
- Episode 34: Episode 34
- Episode 35: Episode 35
- Episode 36: Episode 36
- Episode 37: Episode 37
- Episode 38: Episode 38
- Episode 39: Episode 39
- Episode 40: Episode 40
Who Is the Sender? Season 1 Episode 1
Kuwazuru Mitsuki is a second year student at Arakawa Nishi High School. One day, her homeroom teacher, Tachibana, suddenly announces the start of the "Letter Game", where every student has to write a letter with his/her true feelings to each of the classmates. However, the "letter" will not include the sender's name. At first, there were a lot of bad jokes and silly "letters", but they slowly accelerate to revealing secrets and confessions, which make everyone question, "Who is the sender?" and "Who will be named next?" This game allows the students to become more aware of each other's hidden worries and thoughts, which slowly deepens the bond among the classmates. Meanwhile, Mitsuki tries to search for the sender of the letter sent to her and she discovers a secret hidden in this "letter game".
