For anyone in question here is a link to the chapter and page which starts the regression on page 21: (Start on 20 to get the whole conversion.
http://www.mangapanda.com/medaka-box/171/13 no process just poof happens then they take notice a few panels later) but fairly funny reactions none the less. There is both male and female regression. No baggy clothing just normal clothing changed with there body's stuff. Has good cute plotting in terms of story telling but lacks process.