Sorry fallkwing I just want to reread this now
following
http://www.mangago.zone/read-manga/sono_kuchibiru_itadakimasu/
Its the second story
Thank you (⌒▽⌒)
The sad part is this one is sooooo similar but it's not the one I'm looking for (￣∇￣")
In the one I'm talking about, the girl confesses with a letter. And when finding out that the confession wasn't for him, it's cause he jumped out the window to save the picture she dropped.
The girl is in love with someone and tried to confess but confessed to the wrong person. She ended up confessing to the delinquent everyone is afraid of. He realizes she made a mistake because she lost the picture she was holding on to and crying about and he saw and tells her crush that she made a mistake. But she had already fallen in love with the delinquent.
Thanks! (=・ω・=)