Other/ New Character
Who's the holder of the 4th Key?
Where is the option "Other"? XD
Any of them showed any knowledge about the promise. A new girl is most likely IMO.
Probably new character, I want to see more on this matter soon :P
We have to wait until the start of a new year of school, they are in summer vacation currently, it will be soon.
I know that transfered girl or new students is quite cliche, but we know that it is the most natural way to add new chracters in this kind of series.
Hummmm..I guess it can't be Haru (She saw Raku's Pendant,and it did not stimule any kind of memories/reaction from her).Tsugumi/Mikage are kind of build up as characters new to Raku's life,which mean he never met them 10 years ago..
Paula doesn't know about the Promise,so there is still a possibility for her to be the fourth girl.Won't say "NO" about Ruri either,but it would be too "School days" if she end up restricting her feeling for Raku because of her friendship with Onodera...
Fuu did well in the last Popularity poll,didn't she?And she did not have that big of exposure in the chapters preceding the poll,so maybe Noashi san would use that opportunity and make her the fourth girl?(No please,just no ><)
Well,I guess I'll go with "New character" then...After the Amnesia mini-arc,it nearly became too obvious to me that the promised girl is Chitoge,But I hope the fourth Girl will give everyone a run for their money,well,everyone but Marika