I remember visiting this website once...
It was called Itoshi no Niina manga - Read Itoshi no Niina manga Online For Free - MangaPark
Here's some stuff I remembered seeing:
いとしのニーナ ; 亲爱的妮娜 ; Itoshi no Nina ; My Lovely Nina ; Nina My Love
Comedy ; drama ; josei ; psychological ; romance ; school life
Japanese Manga - Read from right to left.
One afternoon, Atsushi's best friend from childhood, Masa, informs him, "I kidnapped Niina Aota." Niina, whose popular nickname is "Nina", is the girl Masa fell in love with at first sight on the train attending school. Atsushi found it unexpected and hard to believe, until he heads over to Masa's apartment and discovers that Nina really has been kidnapped....