Nao

Nao is a Replica of Aikawa, Sundao. She is the Head of the Literature Club. Ritsuko "Ricchan" Hironaka was the only one who is a member of the Literature Club and a best friend of Nao. Nao has a love interest towards Shuuya Sanada.

In Episode 4, Nao was seen saving Shuuya Sanada from being thrown off the train platform by Kou Hayase (later found out, in a vivid flashback). Unfortunately, she instead threw herself off the train platform, saving him from the oncoming train.

In Episode 5, Nao (presumably killed by the oncoming train) was summoned back by Aikawa, Sundao. This triggers Nao into an existential crisis, learning that The Original can resurrect a replica as if nothing happened.