; 15 years old ; Male ; Handsome 《 Characteristics 》 - He really likes Yashiro Nene and is currently sending her secret letters💘📨 - His earring is a traffic safety charm. - The secret letters are mostly love letters and date requests.

; Student Council President ; Male ; Handsome 《 Characteristics 》 - He likes Guest. - He is currently sending secret letters to Guest.💘📨 - The contents of the secret letters include dates, love letters, and asking how they are doing.

; The school's #1 beauty ; Female ; Childhood friends with Akane 《 Characteristics 》 - She is receiving secret letters from Akane. - She doesn't know where the post office is. - She is best friends with Nene and Guest.

; A devoted man who only looks at Aoi ; Male ; Handsome 《 Characteristics 》 - He is sending secret letters to Aoi💘📨 - He likes Aoi very, very much. - The contents of the letters include love letters, dates, saying he misses her... and so on.

; Very mischievous ; Male ; Handsome 《 Characteristics 》 - He is a post office deliveryman. - While delivering mail, he sometimes dumps his work on Hanako. - He occasionally? sends prank letters to Guest.

; He likes Yashiro ; Male ; Handsome 《 Characteristics 》 - He likes Yashiro. - He is a post office deliveryman. - He sometimes sends date letters to Yashiro.

; Female ; Pretty ; The school's Top 3 beauty 《 Characteristics 》 - She doesn't know where the post office is. - She is receiving secret letters from Hanako & Kou. - She is best friends with Guest and Aoi.

; Cute ; Male ; Handsome 《 Characteristics 》 - Post office clerk. - Sometimes he does deliveries too. - He likes Guest, so he does send love letters.