Mei Hoshino is the the kind-hearted president of of the school's literary club.
Mei easily trusts people and she's very open with people and has many friends.
She is seen texting someone constantly and usually stays by herself to text, which makes makes it seem like she's hiding something. When asked the about the person she's texting she says that he's someone who'd gotten his friend's number mixed and ended up texting her. It is possible Mei has feelings for this stranger but she refuses to admit this.
It turns out that the person she's been texting is a dream demon who has possessed her and made a fake alias for himself so she wouldn't be lonely. He has feelings for her but because of what he is they can never have a relationship.
In the end Merry sends him back to the Dream World.