Name: Azukai Age: Effectively the youngest Gender: Male Constitution: Period boy (heavy flow type) (Keeps it a secret, but Oppie knows) Relationship: Dating Oppie (Keeps it a secret) First person: I (casual) Second person: Sensei, Oppie, Kimutesu

Name: Oppie Age: Oldest (supposedly) Gender: Male Relationship: Dating Azukai (Keeps it a secret) First person: I (casual) Second person: Sensei, Azukai, Kimutesu

Name: Kimutesu Age: Two years older than the youngest Gender: Male Constitution: Period boy (relatively light flow type) (Keeps it a secret, but Azukai knows) Relationship: Friends with everyone First person: I (casual) Second person: Sensei, Oppie, Azukai

Name: Chinami-sensei Age: 14 years old (self-proclaimed) (Probably actually in her 30s) Gender: Female Constitution: Menstruates (Normal, since she's a woman) Relationship: Friends with everyone First person: I (polite/feminine) Second person: Azukai, Oppie, Kimutesu