Following from the success of ONNA2013, the ONNA2015 workshop will be held at OIST Graduate University (http://www.oist.jp) from 25-28 May 2015. The aim of the workshop is to bring together experts and early stage researchers from diverse communities who use optical micro and nanofibers for their research needs, whether it be for quantum, biological or other applications. The number of participants is strictly limited and will be based on application.