Hajimari no Niina

From Shoujo Crusade]:

10-year old Niina is special. This is because she has the memories of her past life as a girl named Chitose still intact. Among these memories is a promise with Chitose's boyfriend which Niina then decides to try and fulfill. But can she really?

Includes the following one-shots:
Koi Baka. (volume 1)
Toda is a really smart girl but has no passion for anything. She admires idiots who are passionate, especially her classmate, Iijima.

Machibito (volume 4)
Komako is a carefree girl, who's pretty incoherent. Whe. a random guy asks her to eat sweet potatoes with him, she can't help but wonder why he pats her head and thanks her everytime.